rallying a minivan, heheheh. Heck, I've done 'dollar runs' (non-competitive hot laps) in our minivan at a couple of autocrosses before... to the horrified looks of the spectators. Didn't have a bad course time either! I've taken the van on road rallies before, but the TSD (time-speed-distance) ones, not the WRC type.
So, it's be the WMRC? The World Minivan Rally Championships? I'd hate to hit a bridge embankment in the family grochery getter though. "Nature of claim?" ;-)
No, normally the very first thing most would do is lift the foot feed, unless you're in cruise control and that's yet another story.
I'm 63 and so it's a bit hard to remember when I first learned the proper action when that rear end starts coming around.
Born in AR so no help there.
I think my first learning experience in this regard was probably in the USAF in NH when they sent us through driving school and as part of the course we had to learn to drive, spin, recover, on an icy runway ramp with some damn expensive hardware sitting nearby.
How about someone out there chiming in with their RWD adverse condition "turn-into-the-skid" early/young learning experience.
Was it at first a natural, instinctive, reaction or was it something you had to learn, be taught?
And how about FWD?
Just what is the FWD recovery technique when you have an automatic transmission (most do) and belatedly discover you're "plowing" (understeering)?
That is the most common adverse condition loss of control event for FWD is it not?
rwd = turn into the skid and keep your foot on the gas, for some great opposite lock, four wheel drift action! The downside is that you can run out of track/road in a hurry. Another tactic is to turn out of the skid, but this will have you swapping ends usually. While this may shed some energy, you would be facing the wrong way.
No, this was taught, not instictive. Your instinct is always to smack the brake pedal in any of those situations.
Your brakes are your enemy in a skid, fwd, awd or rwd.
The point is... how many folks out there know how to handle a RWD properly? Of those who do, how many keep in practice and would be able to use it as intended? Granted, a FWD push is no fun either, but that is where technology comes in in the form of VSC. VSC combined with AWD systems (yes, even ones with your tortured and theoretical FWD bias) is even better.
I'm sure NASCAR drivers would argue that they can react better than an automated system in a FWD vehicle, but the soccer moms and carpooling commuters are not the performance enthusiasts some would have us think.
I guess I'm missing the boat with respect to this FWD vs. RWD stuff (and I'll leave AWD and VSC and all that other stuff to the side).
Is the argument that when a FWD vehicle starts failing to track, it can't be recovered? I thought if you steer into the skid, ie if the back end is comming right, you steer to the right, that you eventually regain control. Am I wrong there? So, you must be talking about what happens if the traction in the front is gone, you can't make a steering recovery...is that the point? In that situation, what do you do - point your wheels in the direction of the center of mass of the car with the foot off the break and wait for deceleration, then make a steering correction?
I thought one of the advantages to FWD is that the balance of weight in a vehicle (unless we are talking mid or rear engine) is in the front, and thus the traction for FWD generally surpassed RWD. I guess there are senarios where the fronts just don't grip anymore, huh?
In snow and rain, I *thought* you're better off in FWD, but I guess I don't understand something fundamentally here.
I do know it's alot harder to do donuts with FWD in the winter, but there is reverse and there is the handbreak to help you there.
Okay, one FWD solution, E-brake, but it must be learned. A second solution was brought up somewhat obliguely, lighten the steering angle. But that second solution doesn't work if the "plowing" is with the steering dead ahead with the roadbed not.
VSC on the Toyota/Lexus would apply both rear brakes of the vehicle isn't following the direction input via understeering. In other words an automatic (rear) E-brake.
FWD vehicles are better in slick conditions for exactly the reason you state. The weight is over the drive wheels. FWD vehicles do have a handling disadvantage though and this is has nothing to do with forward traction in snow. FWD vehicles tend to plow forward when put into an emergency type turn. Its very hard to recover from this because the drive wheels are also the ones that turn. Furthermore, you can get torque steer which means if you step on the gas, only one wheel gets power (due to a differential) and can jerk you to one side of the other.
I find this entire discussion off topic to conversations about a minivan, but Wwest seems determined to beat it into the ground until everybody agrees to buy RWD vans... like the... ummm... well, there are none so I don't get the point.
Halfshafts are the two drivelines that extend from each side of the front differential to each of the front wheels.
With front engine arrangements the front differentials are almost always off-center. That means the halfshafts must be of different lengths.
With lots of engine torque applied the longer halfshaft will "twist" ( ~20 degrees {??}) more than the shorter one causing the wheel attached to the shorter halfshaft to "lead" the opposite wheel.
Just because there are no RWD, or rear torque biased AWD, minivans out there doesn't mean it wouldn't be wise to know of the potential hazards of FWD.
And as you have seen, it would be rather hard to explain these hazards without RWD as an alternative, even if for theoretical comparison only.
"...the longer halfshaft will "twist" ( ~20 degrees {??}) more than the shorter one..."
You ARE kidding, right? Are you seriously saying that the steel halfshafts "twist" relative to each other by up to 20 deg????
Do you have any idea of how much elasticity would have to be in a 30" long halfshaft for it to "twist" 20 deg more than the other? Especially when the two halfshafts are probably no more than 12" different in length? Can you honestly see 20 deg of "twist" in that 12" of length?
I'd like to know what grade of steel is used in the FWD cars you've been exposed to. It would go a long way towards explaining your bias against FWD....
The 20 degrees was a wild axx guess, as you can see, hopefully, by the double "??" attached. The truth is I have no real idea how much twist difference there might be but I can testify as to the highly detrimental effect therefrom.
My first experience was years ago in a rental FWD Cadillac on a two lane road in rural MS. I punched the gas while simultaneously moving into the left lane to pass a farm vehicle.
WOW --- PANIC, the resulting torque steer, for which I was totally and completely unprepared, almost put me into the ditch.
There is enough "twist" difference in those two unequal length shafts to make it obviuos -- even on dry pavement -- when you stomp on it (like attempting to get into traffic from a side road) and it's exacerbated (ooh, that's a good word!) by the fact that you are most likely performing that maneuver with the wheels turned a bit.
For some real fun though, you all need to come down to Dallas for one of our once-or-twice-a-winter icy days. There's some real fun to be had watching folks discover that the 4WD on their beloved SUVs (polished brush guards all aglow) is actually a detriment on glaze ice! WoooEEEE!!! It's the after-the-State-Fair bumper cars for sure.... ;-)
First - yes, I'm well aware of the way torsion bars work. But torsion bars are DESIGNED to twist. Halfshafts are designed NOT to twist. Do you have any idea of the number of differing grades of steel available to an automotive engineer? Twist in halfshafts (resulting from sudden applications of torque) would result in wheel hop as the shaft twists and then rebounds, not torque steer.
Second - Torque steer is due to the differing geometry arising from the unequal lengths of the halfshafts. When the halfshaft is at a 90 deg angle (perpendicular) to the plane of the rotating tire, all of the torque applied by the transaxle to the shaft is transferred to the wheel. Little is lost in the CV joints. But when the shaft is at an angle to the wheel, not all of the torque is transfered. Shafts of differing lengths will result in differing geometries (angle between the shaft and the wheel) resulting in differing torque applied to the wheel. This is why some manufacturers of FWD vehicles go to great lengths to try to ensure that the GEOMETRY on both the left and right sides are the same even when the halfshafts can't be the same length.
In the 62-63 timeframe there was an episode of broken rear axles which if I remember correctly had to do with limited slip differentials and axles that were too rigid. I seem to remember that Pontiac, for one, was replacing broken rear axles with less rigid ones (more "give" ?) under warranty.
Not trying to say, by any means, that my 20 degree quote was a correct one.
My actual experience with this is only with RWD and leaf springs. High torque "winds" up the leaf spring which in turn causes the tire to lose traction and then the spring rebounds, etc, etc.
I suppose the same thing could happen with FWD and coil springs but that had nothing to do whatsoever with torque steering.
Torque steering is strictly the result of disparate "windup" in the driveline for one side versus the other. If the shorter halfshaft is on the left side torque steering will always be exhibited as a steering "bias" toward the right.
For some reason, I think your typical Sienna minivan (back on topic!) will be developing somewhat less torque for the halfshafts to deal with than an early '60s Pontiac.
BTW - I have seen twisted rear axles. My cousin twisted the axles in a Jag rearend; unfortunately, the axles stayed twisted. But took the motive power of a Ford 427 and a very sticky set of tires to do it....
Correct. Longer halfshaft is more perpendicular to the wheel; therefore, more of the torque is applied to the wheel. Torque steer in the direction of the longer shaft.
If the torque steer was the result of twist, some of the torque would be 'lost' in twisting the halfshaft resulting in LESS torque applied to the wheel at that time....until the shaft rebounded resulting in a sudden surge in torque to that wheel. I would think this would be felt as a 'wagging' of the front end from side to side as the halfshaft first twisted and then rebounded. Typical torque steer however is a constant pulling towards one side - the side with the longer (more perpendicular to the wheel) halfshaft.
So a stupid question: doesn't the torque steer issue raise itself when you apply the gas?
I thought that you weren't supposed to make input changes to the control inputs (steering, braking, acceleration) when moving over a slippery surface...
So let's say you are out of control with the fronts not gripping in a FWD, what are you doing applying the gas or for that matter the brakes? Where does the torque steer come into play?
Just when you're dragging or doing time trials on a frozen lakebed?
torque steer (an irate longhorn? Hey, this is Texas!) shows itself when you accelerate. It always felt to me like a jerk in one direction (to the right in my '95 Civic). If we were in physics class and could use the frictionless surface or even one with a measurable coefficient of friction (that stayed constant over the distances in question) then we might be able to settle this discussion with math. Unfortunately, it just doesn't work that way in the real world and so you'll get amateur engineers such as ourselves (I hope none in this discussion are taking money for this!) arguing over what is and is not happening. Heck, even the professional engineers who are paid to figure this stuff out are disagreeing; I know it isn't the bean counters alone accounting for the varying degrees of success of the available solutions that auto makers provide us.
Suffice it to say that the very best steel shafts are twisting, that the geometry undoubtedly enters into it as well, that the tires slip on the road surface (and slide a bit on the wheels as well) to varying degrees, and all these vary in magnitude and effect over the generally short times involved in a torque steer event. Couple that with the fact that the startled-by-torque-driver will, no matter how well trained or conditioned, make changes in the application of power, the angle of the wheels or both. Therein lies the reason that several intelligent, to some degree knowledgeable, and rational people can experience similar circumstances (or contemplate same) and disagree on the reasons behind them.
If you live north of the snowline, as I do, Seattle area, now would be a good time to think serious about disabling your A/C compressor. On my RX300 I simply unplug the refrigerant pressure sensor switch just in front of the radiator. In older models I always unplugged the A/C compressor clutch circuit.
WHY ???
Most modern day automotive A/C systems, most especially those of the automatic climate control variety, will automatically engage the A/C system to help dehumidify the incoming airstream (you wouldn't DARE be in recirulate at this point!).
At moderately cool outside temperatures, down to about 45F, this can often be a great advantage. But below these temperatures the efficiency of the A/C to dehumidify the incoming airstream declines precipetously, until at just above freezing, ~35F, there is NO dehumidification capability whatsoever.
With outside temperatures below 45F your system should never be in recirculate, and should ALWAYS remain in the mode wherein outlet airflow is significantly heated and routed through the footwell outlet ducts, with a portion bled off to the windshield defrost/defog/demist ducts. This latter air flow is there, by factory design, to help (hopefully) keep the interior of the windshield above dewpoint, the point at which condensation begins to form.
If you have a manually operated system then it will be up to you to remember to monitor the outside temperature and be sure the system has the proper airflow routing, footwell only, as the outside temperature declines.
If you happen to have one of the automatic climate control systems designed or manufactured by NipponDenso in Japan, or Denso USA, in the US, Toyota and Lexus for instance, it will be "biased" toward "cooling" mode (airflow outlet to the face and upper body) regardless of COLD outside temperatures and your personal discomfort due to radiant "cooling" from the COLD surrounding landscape.
Again, it will be up to you, as the driver and therefore "protector" of yourself and your passengers, to be extremely vigilent and ALWAYS over-ride the system from "automatic" outlet airflow control mode, to footwell and defrost/defog/demist mode manually when outside temperatures decline below 45F.
Now.
If the outside temperature is below 45F and IF the interior of your windshield beings to fog over, even ever so slightly, you need to take IMMEDIATE action.
1. Turn the temperature control all the way UP, to MAX HEAT. 2. Turn the system Blower all the way to MAXIMUM speed. 3. THEN.... Change the system outlet airflow mode to defrost/defog/demist.
So, why did this happen, why did the windshield start to fog over?
First, let's assume you followed the above instructions and the system was in heating mode, footwell and defrost/defog/demist airflow mode, and NOT IN RECIRCULATE!
At, say, 65MPH on a really cold day your windshield is being quite thoroughly chilled with the COLD airstream impinging on the outside at 65MPH even though there is a significant level of warming airflow from the system flowing its interior surface.
But now you just picked up two sweaty and wet snow skiers and you're headed back down the mountain. Or you were headed up to the slopes and your passengers became stressed out (sweating profusely) due to the ice and snow covered roadbed and the sometimes unavoidable side-slipping of the vehicle.
Cracking a rear window slightly will almost always help move the cool dry air through the vehicle.
If you have not disabled your A/C for wintertime driving there may be yet another cause for the windshield fogging over.
Your A/C system was running but now isn't.
1. It may have shut down of it's own accord, automatically, a few moments ago, due to declining outside temperatures, 35F or below. Many modern systems will do this automatically, with no warning or obvious indication to the operator.
2. You may have just previosuly used the defrost/defog/demist mode, unaware that this mode automatically activates the A/C system to assist in dehumidification. Once you return the system to normal operation the A/C will shutdown provided you have used the control functionality to turn it off.
3. You may have just noticed that the temperatures have declined and manually turned off the useless A/C.
But why would any of these actions lead to windshield fogging to the point of being a real safety issue??
Long story, but first a short version.
When the A/C is operating it will almost always "gather" airborne water vapor onto the evaporator vanes. As more and more moisture accumulates it will eventually become dropletts large enough that gravity overcomes viscosity and then run down the face of the evaporator and out the drain provided for this purpose.
When the A/C compressor is first shut down the temperature of the evaporator surfaces will begin to rise. And remember ALL system inlet airflow, fresh and recirculated, comes through the evaporator. So that thin film of moisture, the film of moisture that had not yet gained enough mass to overcome viscosity, will begin to evaporate into the atmosphere within the passenger cabin.
BINGO!
Cold windshield, high atmospheric humidity.
The windshield begins to fog over!
Modern day exacerbating circumstances...
1. New, less efficient refrigerant.
With the advent of the use of the new less efficient refrigerants automotive designers were fored to come up with ways to make up for the loss of efficiency.
The most obvious way, and the one most often chosen, was to make the evaporator itsself a lot more efficient. The evaporator in my 1984 T-bird had about 2500 square inches of evaporator cooling surface. The one in the newer vehicles is more typically in the range of 10,000 square inches.
More evaporator surface area = more moisture left over to humidify the passenger cabin once the A/C is turned off.
2. Reduce the cabin atmosphere's "exhaust" outflow.
On a minute by minute basis, the less "conditioned" air that leaves the controlled environment the less incoming airflow that must be cooled.
3. Lower the system blower speed.
The slower the airflow moves through the evaporator vanes the more "heat" it gives up. A lower blower speed also results in even less exhaust outflow due to blower induced pressure differentials.
The Lexus car series is very well insulated for sound deadening and wind noise. MY 92 LS400, in fully automatic mode, could be using recirculate for 90% of the flow in the winter or summer, with the indicator light showing "fresh" mode.
If your car is "plowing", under-steering, FWD, AWD, RWD, doesn't matter, the problem is that your front (steering) tires haven't enough traction with the roadbed to move the car in the direction they are "pointed".
If entering a turn led to the problem then "lightening" the turn will always help, otherwise/also applying the rear E-brake would be best.
And by the way, torque steering doesn't necessarily, if ever, relate to FWD hazards on slippery surfaces. Someone (me?) brought it up so that's where the discussion went.
This is entirely unneeded as all modern AC systems will not run the compressor at temps below 45° in any case.
The thing most people need to learn is to shut off the recirculation button and maximize airflow. All too often you see people driving with fogged windows, generally this is the result of not having enough dryer air entering the car.
We exhale a large amount of water vapor, and to your point, it condenses nicely on the cool exterior windows. The point of the air systme is to raise the surface temperature above the dew point of the moist air flowing by or reduce the humidity level to the point where there isn't enough to condense on the cool surfaces.
Disconnecting your AC compressor is doing yourself a disservice as there are many times in temperate areas that the temp is above 45° and you can use the demhumidification it provides.
We can drive, within an hour, from reasonably warm (above 45F) and humid area, to a damn cold and dry area, to go skiing say.
If you start out with your A/C on and then it shuts down (automatically, manually, whatever) as the outside grows colder and dryer.....
And by the way the Lexus automatic A/C shutdown due to outside air temperature is at 35F. At least for the 90, 91, 92, 95 LS, 00 GS, 00 RX and 01 RX for certain.
And the real problem is that the RX A/C indicator doesn't illuminate in defog/defrost/demist mode even though it is ON.
Dryer, fresh, air cannot enter the car without exhausting some of the atmosphere already there, fresh, recirculate, it doesn't matter.
Please, I'm NOT advising anyone to use recirculate mode under any conditions, just making a point.
The problem is that most people do rely on the owners manual or what the dealer has told them.
In most modern day vehicles you MUST turn up the system blower, or lower a rear window slightly, if you want to reasonably rapidly exhaust the cabin's stale atmosphere.
The cabin airflow exhaust port, for all Lexus models I am aware of, is at the bottom of the rear quarter panel. This is a point at which "at speed" there will generally be more air pressure due to vehicular airflow dynamics than can be overcome by extremely low (and QUIET!) blower speeds and air pressure buildup at fresh air inlets at the bottom of the windshield.
The differences depend somewhat on the XLE package you choose, but basically, the XLE Limited has the following that no XLE can have: Parking Assist Lasar Cruise Control Wood-grain steering wheel and shift knob Chrome Accents on Grill, Tailgate, and Side bump rail HID headlights Autodimming driver's side mirror and rearview mirror (actually XLE can have as an accessory) Folding Tray Table between front seats (option on LTD and NA on XLE)
Along with those there are a few options that an XLE LTD has that cannot be combined on an XLE: 17" wheels & VSC, TRAC, Rear-disc brakes, DRL, and Windshield Wiper De-Icer Grid
If you are looking at the AWD models, the XLE AWD cannot combine DVD with Side-curtain airbags and no XLE AWD can get a moonroof. The XLE Limited AWD come standard with the Side-curtains and moonroof and the DVD can be added as an option.
Please, please stay on topic. If I end up deleting a bunch of posts, it's distracting as well. You can find appropriate discussions for these conversations using the search tools at the left. Thanks.
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In regard to fogging windshields. Yikes. Methinks west had a fogging problem in his 1910 Maxwell etched indelibly on his hard disc. Every so often the subject gets caught in "recirc"
Broncoguy stated: "...Along with those there are a few options that an XLE LTD has that cannot be combined on an XLE: 17" wheels & VSC, TRAC, Rear-disc brakes, DRL, and Windshield Wiper De-Icer Grid"
Maybe I misunderstood the above quote, but, PAckage #12 (among others) allows an XLE to be equipped with 17" wheels & VSC, TRAC, Rear-disc brakes, DRL, and Windshield Wiper De-Icer Grid.
Oops, that was not quite right, but the concept is correct.
You can get 17" wheels, DVD, and VSC on an XLE, but not all three at the same time.
Basically, Toyota is not allowing you to package all the XLE options on an XLE. They are always leaving at least one out to force people who want all of them to step up to the XLE Limited and the other Limited extras that customer may not really want.
I saw a Sienna CE in a dealer's showroom today when I went in to check out the new Prius. It was a CE, but it had lots of dealer-installed options: leather ($2500), DVD player ($1800), and window tint ($700). I thought the DVD and window tint in particular were way overpriced; not long ago a got a very professional tinting job on a Caravan for around $200. Anyway, I had trouble seeing anyone pay over $32,000 for a Sienna CE--maybe that's why it was on the showroom floor instead of in someone's driveway.
You should be able to get XLE with options to be close to a limited model except for the six following items:
1. HID head lights 2. Laser cruise control 3. Wood Styled/Leather steering wheel 4. Auto dimming mirrors 5. Park assist (back up and front bummper sensors). 6. And the all important "Limited" badge on the rear hatch (just a joke).
It is very hard to imagin that you cannot order VSC and DVD in the XLE trim.
I became somewhat intrigued and absorbed in the conversation about how to react to ice driving in a fwd. After wading through the extensive "information" about what you shouldn't do if you encounter ice, I'm still not sure how I should respond the next time I'm in this situation.
I have a Sienna (2001) and hit a very sudden and heavy snowstorm crossing into Montana last February. It had been raining cats and dogs and quickly changed to snow and whiteout conditions as I increased in elevation. As I crossed over a bridge, I hit ice and the van started plowing. This was interstate 90 and I was doing about 60, but luckily no other idiots on road but myself. I turned into the slide, the way I had been taught to do, with several very fast back and forth recoveries and was able to keep it on the interstate. I never touched the brakes.. just took my foot off the pedal and rode it out.
I've since moved from Seattle to that same area and will more than likely see this situation again.. I'm not too sure if the "e-brake" on the Sienna would be appropriate unless you were already traveling much slower.
I know! Slowing down would sure help, but black ice almost always causes problems when you don't expect it.
In fact, it's the only bad experience I've had with my Sienna, although I suspect it would have happened in ANY car I had been driving.
Any suggestions on how to react to black ice? I might tryout the e-brake in much slower conditions and NOT on an interstate.
shifting into neutral or NOT getting off the throttle fully. Both will be hard.
Assuming you started "plowing" and then suddenly lifted the throttle instinctively the effect of the throttle lift was most likely to exacerbate your dilema.
Having lived in central MT, Lexistown, for a period of time back in the sixties, before FWD, my advice would be to buy an old junker 4WD PU for wintertime use.
And DO NOT use cruise control if the temperature is below 35F and/or has been hovering around there overnight.
I don't think putting it into neutral would have been an option. The entire incident happened within 1-2 seconds including the recovery.
My primary concern was how the Sienna handled. I lived in Colorado for a couple of years and don't ever remember losing control, or feeling like I was going to lose control, that fast. I had a fwd sedan with a low center of gravity and drove it into the mountains every winter weekend, but never felt like I couldn't control the vehicle when I got into a sliding situation.
After experiencing the slide in the Sienna, I started wondering if it might be a poor candidate for snow/ice driving. I've been seriously thinking about getting an old junker and parking the Sienna during the winter.
Mr Wests missives to the contrary, a FWD vehicle is a fine winter car.
If you live in a winter state where you are likely to encounter such conditions, having 4 snow tires can be of tremendous assistance.
From the sounds of your experience you did very well and ultiimately so did the Sienna. Any vehicle hitting black ice can and will react in a way where you as the driver must intervene to keep or gain control.
Getting off the gas can and will excacerbate the issue on any car. For a front drive car it causes engine braking on the front, for a rear drive it will cause engine braking on the rear wheels. Either one can create an emergency situation that you may or not be able to recover from depending on the severity and available traction.
Although counter intuitive, staying slightly on the gas can minimize the effects of engine braking but ultimately the rest of your inputs are more important.
In a low traction situation, driving carefully with slow inputs (turning the wheel, accelerating, braking) that are not extreme will generally keep you out of trouble.
Having driven front and rear drive vehicles in all manner of weather, I prefer front wheel drive in all situations off a race track. For most any driver who is not a race car driver, a front wheel drive vehicle of any type is what I would recommend, over rear wheel or four wheel drive.
I should comment... that my e-brake remark was made in satire, well partially. I think that e-braking can aid you at a very low speed, but I wouldn't even think about it at anything over say 20mph, if that. The change in direction would be dramatic, to say the least. Tried on the highway if you hit black ice could easily end you in the ditch before you know it.
Kmead has very good advice, in that you should make only small course inputs. Sudden steering/brake/throttle inputs will only quickly overcome your tires' ability to control its direction. If you're on snow or ice sometime in your FWD Sienna (for some sure Sienna content) and stopped in say a deserted parking lot, punch the gas to break the wheels free, and then start sawing the wheel back and forth. You won't change the course of our van much at all. What you will do is just spin the tires while they point left and right... and maybe make a bit of forward progress. My point with that is to show how your spinning wheels will have little effect on steering control. Back in physics classes when studying friction, they tell you that rolling friction of a tire is greater than sliding friction, in most cases. Nothing is absolute, is it?
Anyway, your best bet is to slow down, and decrease your steering and throttle/brake inputs. Completely lifting the throttle will either induce more push (oversteer) because of the front wheels' slight engine braking, or cause what is called lift-throttle oversteer when the weight transfers from rear to front and the rear tires lose traction. Neither of which you want to happen.
I still believe that 99% or more of drivers are better off w/a fwd vehicle (such as a Sienna) in almost all winter driving situations.
In a FWD, the most likely way to lose control is loss of traction at the front. Once that happens your ONLY choice is to somehow regain traction at the front.
Obviously, slowing the car will always help. And a SLIGHT application of the rear e-brake will therefore help doubly. Remembering that it was the front that initially lost traction we can very likely rely on still having some level of useful traction available at the rear.
So LIGHTLY applying the rear e-brake will both help to slow the vehicle and at the same time help to pull the car back "on-track". Think of it as throwing a "drag" anchor out the back of a boat drifting downriver.
The other possibility is that the front loss of traction was a result of driver over-control, steering too hard on a slippery surface. Obviously in that case a reduction of the steering angle will help dramatically.
So, you happened to be headed for the edge of a dropoff is why so much steering input. A reduction in the steering rate along with slowing the car via rear braking is your most likely "savior". Once traction is regained and hopefully the vehicle has slowed you will have a better chance of avoiding that dropoff.
But, a bit of bad news. Loss of traction on a FWD vehicle can be much harder to detect as soon as it occurs vs RWD loss of traction. With only the rear wheels driven, a loss of traction at the rear will very quickly result in the rear trying to pass the front. Once detected, a slight lift of the gas pedal coupled with slight steering input, into the skid (there's that dropoff ahead again!), will quickly get you back on track.
In a FWD vehicle traveling straight down the road the most likely way you will discover a loss of traction at the front is loss of gas pedal "feel" (hopefully you're not using cruise control, in which case loss of traction detection will be delayed until you are well into the first "spin"). The car seems to be slowing and more gas doesn't help.
To move down the road safely and in control you need the ability to steer the car and you need a way to deliver the engine torque to the roadbed. Asking the front tires to do both is all well and good in AZ provided you never go where the snow and ice is.
The very minute you hit that black ice or icy bridge deck is when you want a separate set of tires allocated for driving vs steering.
And in closing, remember mooretorque's law, the better 4WD you have the deeper into the woods you get before getting STUCK. FWD is simply a really cheap form of 4WD, with engine weight in front they will ALWAYS have better traction for get up and go than a light rear-ended RWD.
Rear torque biased AWD will ALWAYS be the best choice overall, say as in the new 4runner. At least until the Stability systems, VSC, PSM, etc, get coupled in and engine driving torque to the front is reduced as a function of lateral loading at the front.
For those of you who INSIST on purchasing and driving FWD vehicles, or AWD with front torque biasing, Highlander, RX300, MDX, Sienna, etc, I would suggest you very seriously consider one with a CLUTCH, or if not do some serious practising at quickly shifting the transmission into neutral.
Or don't go out in sub-freezing or near sub-freezing weather.
Or here's a new idea to add to ABS pumpmotor functionality along with BA, Brake Assist.
Brake Assist:
The industry has decided that many of us are too timid about fully applying the brakes in a panic situation so they now detect our initial rate of brake application and if its high enough they step in and FULLY apply the brakes even if we haven't.
So why not...
On QUICK or RAPID throttle lift with FWD or front biased AWD apply the rear brakes slightly to simulate the inherent directional stability of RWD!
Has anyone noticed that one of the new BMW's will actually take over the steering and counter-steer if it detects impending under-steering?
For those of you who INSIST on purchasing and driving FWD vehicles, or AWD with front torque biasing, Highlander, RX300, MDX, Sienna, etc, I would suggest you very seriously consider one with a CLUTCH...
How many Highlanders, RX300s, MDXs, Siennas do you know of that come with a clutch? What percentage of ALL cars these days, especially SUVs and minivans, and AWD vehicles, have a clutch?
Comments
So, it's be the WMRC? The World Minivan Rally Championships? I'd hate to hit a bridge embankment in the family grochery getter though. "Nature of claim?" ;-)
I'm 63 and so it's a bit hard to remember when I first learned the proper action when that rear end starts coming around.
Born in AR so no help there.
I think my first learning experience in this regard was probably in the USAF in NH when they sent us through driving school and as part of the course we had to learn to drive, spin, recover, on an icy runway ramp with some damn expensive hardware sitting nearby.
How about someone out there chiming in with their RWD adverse condition "turn-into-the-skid" early/young learning experience.
Was it at first a natural, instinctive, reaction or was it something you had to learn, be taught?
And how about FWD?
Just what is the FWD recovery technique when you have an automatic transmission (most do) and belatedly discover you're "plowing" (understeering)?
That is the most common adverse condition loss of control event for FWD is it not?
fwd = e-brake to counter a push condition.
rwd = turn into the skid and keep your foot on the gas, for some great opposite lock, four wheel drift action! The downside is that you can run out of track/road in a hurry. Another tactic is to turn out of the skid, but this will have you swapping ends usually. While this may shed some energy, you would be facing the wrong way.
No, this was taught, not instictive. Your instinct is always to smack the brake pedal in any of those situations.
Your brakes are your enemy in a skid, fwd, awd or rwd.
Steve, Host
I'm sure NASCAR drivers would argue that they can react better than an automated system in a FWD vehicle, but the soccer moms and carpooling commuters are not the performance enthusiasts some would have us think.
Is the argument that when a FWD vehicle starts failing to track, it can't be recovered? I thought if you steer into the skid, ie if the back end is comming right, you steer to the right, that you eventually regain control. Am I wrong there? So, you must be talking about what happens if the traction in the front is gone, you can't make a steering recovery...is that the point? In that situation, what do you do - point your wheels in the direction of the center of mass of the car with the foot off the break and wait for deceleration, then make a steering correction?
I thought one of the advantages to FWD is that the balance of weight in a vehicle (unless we are talking mid or rear engine) is in the front, and thus the traction for FWD generally surpassed RWD. I guess there are senarios where the fronts just don't grip anymore, huh?
In snow and rain, I *thought* you're better off in FWD, but I guess I don't understand something fundamentally here.
I do know it's alot harder to do donuts with FWD in the winter, but there is reverse and there is the handbreak to help you there.
VSC on the Toyota/Lexus would apply both rear brakes of the vehicle isn't following the direction input via understeering. In other words an automatic (rear) E-brake.
I find this entire discussion off topic to conversations about a minivan, but Wwest seems determined to beat it into the ground until everybody agrees to buy RWD vans... like the... ummm... well, there are none so I don't get the point.
Halfshafts are the two drivelines that extend from each side of the front differential to each of the front wheels.
With front engine arrangements the front differentials are almost always off-center. That means the halfshafts must be of different lengths.
With lots of engine torque applied the longer halfshaft will "twist" ( ~20 degrees {??}) more than the shorter one causing the wheel attached to the shorter halfshaft to "lead" the opposite wheel.
Just because there are no RWD, or rear torque biased AWD, minivans out there doesn't mean it wouldn't be wise to know of the potential hazards of FWD.
And as you have seen, it would be rather hard to explain these hazards without RWD as an alternative, even if for theoretical comparison only.
You ARE kidding, right? Are you seriously saying that the steel halfshafts "twist" relative to each other by up to 20 deg????
Do you have any idea of how much elasticity would have to be in a 30" long halfshaft for it to "twist" 20 deg more than the other? Especially when the two halfshafts are probably no more than 12" different in length? Can you honestly see 20 deg of "twist" in that 12" of length?
I'd like to know what grade of steel is used in the FWD cars you've been exposed to. It would go a long way towards explaining your bias against FWD....
My first experience was years ago in a rental FWD Cadillac on a two lane road in rural MS. I punched the gas while simultaneously moving into the left lane to pass a farm vehicle.
WOW --- PANIC, the resulting torque steer, for which I was totally and completely unprepared, almost put me into the ditch.
For some real fun though, you all need to come down to Dallas for one of our once-or-twice-a-winter icy days. There's some real fun to be had watching folks discover that the 4WD on their beloved SUVs (polished brush guards all aglow) is actually a detriment on glaze ice! WoooEEEE!!! It's the after-the-State-Fair bumper cars for sure.... ;-)
Second - Torque steer is due to the differing geometry arising from the unequal lengths of the halfshafts. When the halfshaft is at a 90 deg angle (perpendicular) to the plane of the rotating tire, all of the torque applied by the transaxle to the shaft is transferred to the wheel. Little is lost in the CV joints. But when the shaft is at an angle to the wheel, not all of the torque is transfered. Shafts of differing lengths will result in differing geometries (angle between the shaft and the wheel) resulting in differing torque applied to the wheel. This is why some manufacturers of FWD vehicles go to great lengths to try to ensure that the GEOMETRY on both the left and right sides are the same even when the halfshafts can't be the same length.
Not trying to say, by any means, that my 20 degree quote was a correct one.
I suppose the same thing could happen with FWD and coil springs but that had nothing to do whatsoever with torque steering.
Torque steering is strictly the result of disparate "windup" in the driveline for one side versus the other. If the shorter halfshaft is on the left side torque steering will always be exhibited as a steering "bias" toward the right.
BTW - I have seen twisted rear axles. My cousin twisted the axles in a Jag rearend; unfortunately, the axles stayed twisted. But took the motive power of a Ford 427 and a very sticky set of tires to do it....
If the torque steer was the result of twist, some of the torque would be 'lost' in twisting the halfshaft resulting in LESS torque applied to the wheel at that time....until the shaft rebounded resulting in a sudden surge in torque to that wheel. I would think this would be felt as a 'wagging' of the front end from side to side as the halfshaft first twisted and then rebounded. Typical torque steer however is a constant pulling towards one side - the side with the longer (more perpendicular to the wheel) halfshaft.
Hey....how 'bout those Siennas?
So a stupid question: doesn't the torque steer issue raise itself when you apply the gas?
I thought that you weren't supposed to make input changes to the control inputs (steering, braking, acceleration) when moving over a slippery surface...
So let's say you are out of control with the fronts not gripping in a FWD, what are you doing applying the gas or for that matter the brakes? Where does the torque steer come into play?
Just when you're dragging or doing time trials on a frozen lakebed?
Suffice it to say that the very best steel shafts are twisting, that the geometry undoubtedly enters into it as well, that the tires slip on the road surface (and slide a bit on the wheels as well) to varying degrees, and all these vary in magnitude and effect over the generally short times involved in a torque steer event. Couple that with the fact that the startled-by-torque-driver will, no matter how well trained or conditioned, make changes in the application of power, the angle of the wheels or both. Therein lies the reason that several intelligent, to some degree knowledgeable, and rational people can experience similar circumstances (or contemplate same) and disagree on the reasons behind them.
WHY ???
Most modern day automotive A/C systems, most especially those of the automatic climate control variety, will automatically engage the A/C system to help dehumidify the incoming airstream (you wouldn't DARE be in recirulate at this point!).
At moderately cool outside temperatures, down to about 45F, this can often be a great advantage. But below these temperatures the efficiency of the A/C to dehumidify the incoming airstream declines precipetously, until at just above freezing, ~35F, there is NO dehumidification capability whatsoever.
With outside temperatures below 45F your system should never be in recirculate, and should ALWAYS remain in the mode wherein outlet airflow is significantly heated and routed through the footwell outlet ducts, with a portion bled off to the windshield defrost/defog/demist ducts. This latter air flow is there, by factory design, to help (hopefully) keep the interior of the windshield above dewpoint, the point at which condensation begins to form.
If you have a manually operated system then it will be up to you to remember to monitor the outside temperature and be sure the system has the proper airflow routing, footwell only, as the outside temperature declines.
If you happen to have one of the automatic climate control systems designed or manufactured by NipponDenso in Japan, or Denso USA, in the US, Toyota and Lexus for instance, it will be "biased" toward "cooling" mode (airflow outlet to the face and upper body) regardless of COLD outside temperatures and your personal discomfort due to radiant "cooling" from the COLD surrounding landscape.
Again, it will be up to you, as the driver and therefore "protector" of yourself and your passengers, to be extremely vigilent and ALWAYS over-ride the system from "automatic" outlet airflow control mode, to footwell and defrost/defog/demist mode manually when outside temperatures decline below 45F.
Now.
If the outside temperature is below 45F and IF the interior of your windshield beings to fog over, even ever so slightly, you need to take IMMEDIATE action.
1. Turn the temperature control all the way UP, to MAX HEAT.
2. Turn the system Blower all the way to MAXIMUM speed.
3. THEN....
Change the system outlet airflow mode to defrost/defog/demist.
So, why did this happen, why did the windshield start to fog over?
First, let's assume you followed the above instructions and the system was in heating mode, footwell and defrost/defog/demist airflow mode, and NOT IN RECIRCULATE!
At, say, 65MPH on a really cold day your windshield is being quite thoroughly chilled with the COLD airstream impinging on the outside at 65MPH even though there is a significant level of warming airflow from the system flowing its interior surface.
But now you just picked up two sweaty and wet snow skiers and you're headed back down the mountain. Or you were headed up to the slopes and your passengers became stressed out (sweating profusely) due to the ice and snow covered roadbed and the sometimes unavoidable side-slipping of the vehicle.
Moisture = higher humidity + a cool windshield surface = condensation.
Cracking a rear window slightly will almost always help move the cool dry air through the vehicle.
If you have not disabled your A/C for wintertime driving there may be yet another cause for the windshield fogging over.
Your A/C system was running but now isn't.
1. It may have shut down of it's own accord, automatically, a few moments ago, due to declining outside temperatures, 35F or below. Many modern systems will do this automatically, with no warning or obvious indication to the operator.
2. You may have just previosuly used the defrost/defog/demist mode, unaware that this mode automatically activates the A/C system to assist in dehumidification. Once you return the system to normal operation the A/C will shutdown provided you have used the control functionality to turn it off.
3. You may have just noticed that the temperatures have declined and manually turned off the useless A/C.
But why would any of these actions lead to windshield fogging to the point of being a real safety issue??
Long story, but first a short version.
When the A/C is operating it will almost always "gather" airborne water vapor onto the evaporator vanes. As more and more moisture accumulates it will eventually become dropletts large enough that gravity overcomes viscosity and then run down the face of the evaporator and out the drain provided for this purpose.
When the A/C compressor is first shut down the temperature of the evaporator surfaces will begin to rise. And remember ALL system inlet airflow, fresh and recirculated, comes through the evaporator. So that thin film of moisture, the film of moisture that had not yet gained enough mass to overcome viscosity, will begin to evaporate into the atmosphere within the passenger cabin.
BINGO!
Cold windshield, high atmospheric humidity.
The windshield begins to fog over!
Modern day exacerbating circumstances...
1. New, less efficient refrigerant.
With the advent of the use of the new less efficient refrigerants automotive designers were fored to come up with ways to make up for the loss of efficiency.
The most obvious way, and the one most often chosen, was to make the evaporator itsself a lot more efficient. The evaporator in my 1984 T-bird had about 2500 square inches of evaporator cooling surface. The one in the newer vehicles is more typically in the range of 10,000 square inches.
More evaporator surface area = more moisture left over to humidify the passenger cabin once the A/C is turned off.
2. Reduce the cabin atmosphere's "exhaust" outflow.
On a minute by minute basis, the less "conditioned" air that leaves the controlled environment the less incoming airflow that must be cooled.
3. Lower the system blower speed.
The slower the airflow moves through the evaporator vanes the more "heat" it gives up. A lower blower speed also results in even less exhaust outflow due to blower induced pressure differentials.
The Lexus car series is very well insulated for sound deadening and wind noise. MY 92 LS400, in fully automatic mode, could be using recirculate for 90% of the flow in the winter or summer, with the indicator light showing "fresh" mode.
If entering a turn led to the problem then "lightening" the turn will always help, otherwise/also applying the rear E-brake would be best.
And by the way, torque steering doesn't necessarily, if ever, relate to FWD hazards on slippery surfaces. Someone (me?) brought it up so that's where the discussion went.
I've been looking all over my keyboard here and I can't find the "e-brake" anywhere!?!
But then I recently heard some folks have trouble finding "it".
The thing most people need to learn is to shut off the recirculation button and maximize airflow. All too often you see people driving with fogged windows, generally this is the result of not having enough dryer air entering the car.
We exhale a large amount of water vapor, and to your point, it condenses nicely on the cool exterior windows. The point of the air systme is to raise the surface temperature above the dew point of the moist air flowing by or reduce the humidity level to the point where there isn't enough to condense on the cool surfaces.
Disconnecting your AC compressor is doing yourself a disservice as there are many times in temperate areas that the temp is above 45° and you can use the demhumidification it provides.
We can drive, within an hour, from reasonably warm (above 45F) and humid area, to a damn cold and dry area, to go skiing say.
If you start out with your A/C on and then it shuts down (automatically, manually, whatever) as the outside grows colder and dryer.....
And by the way the Lexus automatic A/C shutdown due to outside air temperature is at 35F. At least for the 90, 91, 92, 95 LS, 00 GS, 00 RX and 01 RX for certain.
And the real problem is that the RX A/C indicator doesn't illuminate in defog/defrost/demist mode even though it is ON.
Please, I'm NOT advising anyone to use recirculate mode under any conditions, just making a point.
The problem is that most people do rely on the owners manual or what the dealer has told them.
In most modern day vehicles you MUST turn up the system blower, or lower a rear window slightly, if you want to reasonably rapidly exhaust the cabin's stale atmosphere.
The cabin airflow exhaust port, for all Lexus models I am aware of, is at the bottom of the rear quarter panel. This is a point at which "at speed" there will generally be more air pressure due to vehicular airflow dynamics than can be overcome by extremely low (and QUIET!) blower speeds and air pressure buildup at fresh air inlets at the bottom of the windshield.
Sorry Steve, slightly off-topic, but I couldn't resist.
VS7
The differences depend somewhat on the XLE package you choose, but basically, the XLE Limited has the following that no XLE can have:
Parking Assist
Lasar Cruise Control
Wood-grain steering wheel and shift knob
Chrome Accents on Grill, Tailgate, and Side bump rail
HID headlights
Autodimming driver's side mirror and rearview mirror (actually XLE can have as an accessory)
Folding Tray Table between front seats (option on LTD and NA on XLE)
Along with those there are a few options that an XLE LTD has that cannot be combined on an XLE:
17" wheels & VSC, TRAC, Rear-disc brakes, DRL, and Windshield Wiper De-Icer Grid
If you are looking at the AWD models, the XLE AWD cannot combine DVD with Side-curtain airbags and no XLE AWD can get a moonroof. The XLE Limited AWD come standard with the Side-curtains and moonroof and the DVD can be added as an option.
kirstie_h
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"...Along with those there are a few options that an XLE LTD has that cannot be combined on an XLE:
17" wheels & VSC, TRAC, Rear-disc brakes, DRL, and Windshield Wiper De-Icer Grid"
Maybe I misunderstood the above quote, but,
PAckage #12 (among others) allows an XLE to be equipped with 17" wheels & VSC, TRAC, Rear-disc brakes, DRL, and Windshield Wiper De-Icer Grid.
-Howard
You can get 17" wheels, DVD, and VSC on an XLE, but not all three at the same time.
Basically, Toyota is not allowing you to package all the XLE options on an XLE. They are always leaving at least one out to force people who want all of them to step up to the XLE Limited and the other Limited extras that customer may not really want.
1. HID head lights
2. Laser cruise control
3. Wood Styled/Leather steering wheel
4. Auto dimming mirrors
5. Park assist (back up and front bummper sensors).
6. And the all important "Limited" badge on the rear hatch (just a joke).
It is very hard to imagin that you cannot order VSC and DVD in the XLE trim.
I have a Sienna (2001) and hit a very sudden and heavy snowstorm crossing into Montana last February. It had been raining cats and dogs and quickly changed to snow and whiteout conditions as I increased in elevation. As I crossed over a bridge, I hit ice and the van started plowing. This was interstate 90 and I was doing about 60, but luckily no other idiots on road but myself. I turned into the slide, the way I had been taught to do, with several very fast back and forth recoveries and was able to keep it on the interstate. I never touched the brakes.. just took my foot off the pedal and rode it out.
I've since moved from Seattle to that same area and will more than likely see this situation again.. I'm not too sure if the "e-brake" on the Sienna would be appropriate unless you were already traveling much slower.
I know! Slowing down would sure help, but black ice almost always causes problems when you don't expect it.
In fact, it's the only bad experience I've had with my Sienna, although I suspect it would have happened in ANY car I had been driving.
Any suggestions on how to react to black ice? I might tryout the e-brake in much slower conditions and NOT on an interstate.
.
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Assuming you started "plowing" and then suddenly lifted the throttle instinctively the effect of the throttle lift was most likely to exacerbate your dilema.
Having lived in central MT, Lexistown, for a period of time back in the sixties, before FWD, my advice would be to buy an old junker 4WD PU for wintertime use.
And DO NOT use cruise control if the temperature is below 35F and/or has been hovering around there overnight.
My primary concern was how the Sienna handled. I lived in Colorado for a couple of years and don't ever remember losing control, or feeling like I was going to lose control, that fast. I had a fwd sedan with a low center of gravity and drove it into the mountains every winter weekend, but never felt like I couldn't control the vehicle when I got into a sliding situation.
After experiencing the slide in the Sienna, I started wondering if it might be a poor candidate for snow/ice driving. I've been seriously thinking about getting an old junker and parking the Sienna during the winter.
.
If you live in a winter state where you are likely to encounter such conditions, having 4 snow tires can be of tremendous assistance.
From the sounds of your experience you did very well and ultiimately so did the Sienna. Any vehicle hitting black ice can and will react in a way where you as the driver must intervene to keep or gain control.
Getting off the gas can and will excacerbate the issue on any car. For a front drive car it causes engine braking on the front, for a rear drive it will cause engine braking on the rear wheels. Either one can create an emergency situation that you may or not be able to recover from depending on the severity and available traction.
Although counter intuitive, staying slightly on the gas can minimize the effects of engine braking but ultimately the rest of your inputs are more important.
In a low traction situation, driving carefully with slow inputs (turning the wheel, accelerating, braking) that are not extreme will generally keep you out of trouble.
Having driven front and rear drive vehicles in all manner of weather, I prefer front wheel drive in all situations off a race track. For most any driver who is not a race car driver, a front wheel drive vehicle of any type is what I would recommend, over rear wheel or four wheel drive.
Kmead has very good advice, in that you should make only small course inputs. Sudden steering/brake/throttle inputs will only quickly overcome your tires' ability to control its direction. If you're on snow or ice sometime in your FWD Sienna (for some sure Sienna content) and stopped in say a deserted parking lot, punch the gas to break the wheels free, and then start sawing the wheel back and forth. You won't change the course of our van much at all. What you will do is just spin the tires while they point left and right... and maybe make a bit of forward progress. My point with that is to show how your spinning wheels will have little effect on steering control. Back in physics classes when studying friction, they tell you that rolling friction of a tire is greater than sliding friction, in most cases. Nothing is absolute, is it?
Anyway, your best bet is to slow down, and decrease your steering and throttle/brake inputs. Completely lifting the throttle will either induce more push (oversteer) because of the front wheels' slight engine braking, or cause what is called lift-throttle oversteer when the weight transfers from rear to front and the rear tires lose traction. Neither of which you want to happen.
I still believe that 99% or more of drivers are better off w/a fwd vehicle (such as a Sienna) in almost all winter driving situations.
Obviously, slowing the car will always help. And a SLIGHT application of the rear e-brake will therefore help doubly. Remembering that it was the front that initially lost traction we can very likely rely on still having some level of useful traction available at the rear.
So LIGHTLY applying the rear e-brake will both help to slow the vehicle and at the same time help to pull the car back "on-track". Think of it as throwing a "drag" anchor out the back of a boat drifting downriver.
The other possibility is that the front loss of traction was a result of driver over-control, steering too hard on a slippery surface. Obviously in that case a reduction of the steering angle will help dramatically.
So, you happened to be headed for the edge of a dropoff is why so much steering input. A reduction in the steering rate along with slowing the car via rear braking is your most likely "savior". Once traction is regained and hopefully the vehicle has slowed you will have a better chance of avoiding that dropoff.
But, a bit of bad news. Loss of traction on a FWD vehicle can be much harder to detect as soon as it occurs vs RWD loss of traction. With only the rear wheels driven, a loss of traction at the rear will very quickly result in the rear trying to pass the front. Once detected, a slight lift of the gas pedal coupled with slight steering input, into the skid (there's that dropoff ahead again!), will quickly get you back on track.
In a FWD vehicle traveling straight down the road the most likely way you will discover a loss of traction at the front is loss of gas pedal "feel" (hopefully you're not using cruise control, in which case loss of traction detection will be delayed until you are well into the first "spin"). The car seems to be slowing and more gas doesn't help.
To move down the road safely and in control you need the ability to steer the car and you need a way to deliver the engine torque to the roadbed. Asking the front tires to do both is all well and good in AZ provided you never go where the snow and ice is.
The very minute you hit that black ice or icy bridge deck is when you want a separate set of tires allocated for driving vs steering.
And in closing, remember mooretorque's law, the better 4WD you have the deeper into the woods you get before getting STUCK. FWD is simply a really cheap form of 4WD, with engine weight in front they will ALWAYS have better traction for get up and go than a light rear-ended RWD.
Rear torque biased AWD will ALWAYS be the best choice overall, say as in the new 4runner. At least until the Stability systems, VSC, PSM, etc, get coupled in and engine driving torque to the front is reduced as a function of lateral loading at the front.
Or don't go out in sub-freezing or near sub-freezing weather.
Or here's a new idea to add to ABS pumpmotor functionality along with BA, Brake Assist.
Brake Assist:
The industry has decided that many of us are too timid about fully applying the brakes in a panic situation so they now detect our initial rate of brake application and if its high enough they step in and FULLY apply the brakes even if we haven't.
So why not...
On QUICK or RAPID throttle lift with FWD or front biased AWD apply the rear brakes slightly to simulate the inherent directional stability of RWD!
Has anyone noticed that one of the new BMW's will actually take over the steering and counter-steer if it detects impending under-steering?
Not for me!
How many Highlanders, RX300s, MDXs, Siennas do you know of that come with a clutch? What percentage of ALL cars these days, especially SUVs and minivans, and AWD vehicles, have a clutch?
Steve, Host