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From an engineering standpoint it's quite simple. First, remember that this is an electro-mechanical system, not a mechanical only system. If it was mechanical only then you would be correct. The Fusion has ETC so the computer knows the throttle position. It also knows the steering angle. If you accelerate while turning the computer says "hey - there might be a loss of traction" so it tells the center diff to shift torque to the rear wheels - BEFORE IT ACTUALLY STARTS TO SLIP.
It has nothing to do with whether the front wheels would actually slip or not - it doesn't matter. It shifts the torque to prevent a POSSIBLE slip.
If BMW's AWD system doesn't work that way then maybe they need to license the technology from Ford.
It does both - shifts torque when slippage is detected AND shifts torque when slippage is expected.
I'm sure Ford is losing a few sales over lack of SC in the Fusion. But that doesn't mean they're behind the curve from a technology standpoint. SC was available in 1999 on the Lincoln LS (as was manumatic shifting) so the technology is there. They were also the first to put roll stability control on a SUV IIRC.
You could argue the same thing about the Camcord's lack of AWD. Ford decided to spend the money on AWD while Toyota and Honda spent it on 4 channel ABS and SC. And just because YOU prefer SC over AWD doesn't mean everyone does.
Next year the Fusion will have both AWD and SC. Where does that leave the Camcords?
Because this would make them the first manufacturer on the face of the planet to predict slip "before" it occurs and that ain't so. You cannot predict "slip" any more than you can predict the stock market.
It has nothing to do with whether the front wheels would actually slip or not - it doesn't matter. It shifts the torque to prevent a POSSIBLE slip.
They can say whatever they want different systems work differently. But I'll repeat....Slip can not be predicted and therefore proactive shift of torque to prevent slip is an impossibility.
One example of engaging all wheels proactively (as in... no need to detect slippage before doing so) in an AWD system is Honda's VTM-4. But, it doesn't know if a slippage will occur. It will simply engage all wheels when the vehicle is being accelerated. There might be other systems like it, but so far I haven't found anything that suggests Ford's AWD in Fusion/Milan works like that (or engages without detecting any loss of traction). I will now leave that for akirby to provide us with the details.
In that case evey AWD/4WD system should be called a "reactive" system. Even a full time system like those in Subarus are reacting to something electronic or mechanical in the driveline. Akirby's point is that 4WD can be engaged in the Fusion without slippage of the front wheels. Our Explorer has the same system, but for RWD, and I do feel the rear wheels slip in snow, ice, and sometimes rain before the front wheels kick in too. What I don't feel is when it might be kicking in going around a bend or something like that. But the part you really need it for IMO, which would be getting better traction in slippery conditions, is totally reactive and you can feel the wheels slip a little at first.
Does that make a little more sense or am I just adding to the confusion?
Of course Ford is well behind the curve on things like SC systems.
Whoa now captain. They may be behind in offering in on their fleet of cars but all of the SUVs/CUVs, and optional on some cars now, have it standard. And what Ford uses is not the same animal as what other mfrs offer.
Look up Volvo's SC with RSC system and you'll see the difference right away. Most mfrs are now copying it but I have yet to hear of one that's better than what Volvo and therefore Ford use.
That seems really silly to have it work that way. Why not just send a little power to the other two wheels all the time rather than programming it to start from 0% and work up from there each time the accelerator is depressed? Is it a cost savings thing so they don't have to add another clutch or something? :confuse:
I posted the link in post 7051. Here it is again:
Ford Media Article
Where do you get that incorrect idea, impression, and opinion?
Slip can not be predicted and therefore proactive shift of torque to prevent slip is an impossibility.
You are absolutely totally missing the point. Slip is most likely to occur when accelerating briskly or when cornering. Doesn't mean that it will occur - just that it's possible or even likely depending the road conditions. Ford's AWD software senses one or both of those conditions and sends torque to the rear to AVOID a potential slip situation.
Why is that so hard to comprehend? All you need is a steering angle sensor, throttle sensor, electrically controlled center diff and some softwtare. It's not rocket science.
Ok, I understand what you are saying. The Ford system detects acceleration shifts accordingly. That is different than saying it is able to predict slippage.
As a comparision, Subaru's system has been doing that for years. I posted a description in this thread earlier.
Accord (based on history--current model is a new design)
Camry I4
Fusion
Milan
Passat V6
Prius
Sonata
Those cover a very large percentage of cars sold in this segment. Several others are at least average:
Malibu (pre-2008 model)
Mazda6
Galant
G6
Altima, Aura, Optima, and Avenger/Sebring are too new for CR to have enough data to rate them for reliability. Altima has historically been reliable.
VTM-4 does allow a lock mode to engage all wheels permanently, and will keep it that way for as long as you choose to drive under 18 mph. :P
Umm....how about the entire last paragraph? Try this:
Simple mechanical systems use a clutch to send torque to the secondary drive axle when the primary axle starts to slip. Today’s electronic systems — like those found on all Ford Motor Company cars as well as Ford Explorer and Expedition, the Lincoln Navigator and the V-8 Mercury Mountaineer — use a computer controller that monitors such things as steering angle, accelerator pedal position and engine speed to provide the precise amount of torque, front to rear, as needed.
“What’s really impressive about these systems is that they don’t just react to slip,” says Rodrigues. “They usually prevent that slip from occurring in the first place. By predicting slip and preventing it, the driver doesn’t feel the vehicle slipping and responding. The operation is seamless.”
He says on-demand systems create a smooth, confident driving feel in all weather conditions with much better traction. The systems also help balance and improve driving dynamics by sending torque to the secondary axle when it’s most appropriate for handling.
“On a normal front-drive vehicle, the front wheels have a limited amount of traction available to them,” says Rodrigues. “That traction has to be used for moving the car forward and for steering. If you use all of the torque to drive forward, you don’t have anything left to steer with, and vise versa. An AWD system off-loads some of that drive torque to the rear wheels. The harder you accelerate, the more of that torque that’s going to be redirected to the rear wheels, restoring the ability of the front wheels to steer the vehicle while providing an even higher level of acceleration.”
The paragraph/link from Ford PR is emphasizing on seamlessness/transparency of the system, not on how it works or when it works.
Because in a low traction situation, all the wheels may be going different speeds (as picked up by ABS sensors) so the AWD system knows full well the traction level.
The car can also know if the lights are on, wipers are on (especially BMWs with rain sensors) and if hte defroster/AC is on.
You get a cigar. Thank you for proving my point. Systems don't predict slip they measure it. The only reason the wheels are going different speeds is because they are already slipping. :shades
I have experienced more benefit from AWD rather then SC. Is SC control nice, and effective? Yes. But, in my neck on the woods (North East) AWD will help me more, being we have curvey roads and snow.
Haldex differs from SH-AWD, Quattro, and Symmetrical AWD because it is part time. Is it as sophisticated at the others? No. Is it effective? Yes. Haldex is the best responding part time AWD system in the industry. The benefits are longer tire life and better gas mileage.
Good grief. It's right there in black and white:
use a computer controller that monitors such things as steering angle, accelerator pedal position and engine speed to provide the precise amount of torque, front to rear, as needed.
They're not going to publish the exact algorithm - that's obviously proprietary. Suffice it to say if you're cruising at 30 mph and go WOT - it will engage the rear wheels to avoid slippage. If you accelerate while turning with enough throttle and/or steering angle it will engage the rear wheels to help handling and avoid slipping in case the roads are slick. If you're doing 15 mph in a parking lot at full steering lock with 10% throttle it's not going to engage.
Is it that hard to imagine the situations where you might have wheel slip on a slick road? That's all the software is doing using the steering angle, throttle and speed indicators.
That was true for the Five Hundred originally, but not anymore and never for the Fusion. Ford's AWD system is NOT built by Haldex. It is built in-house and is based on the Haldex system but it works differently.
The Ford technology, Kurrle says, is simpler than the Haldex system because it is “more electro mechanical (and) the Haldex is more of a pressure, hydraulic-based” system.
The fact that it's electro-mechanical is what allows it to be proactive and reactive instead of only being reactive to slip.
You haven’t addressed the issue, but keep repeating excerpts from the link (which shows nothing to the effect I’m looking for). If it is pro-active in any way, what condition is it looking for? I haven’t found anything on the subject, and apparently, that article is all you’re relying on for knowledge as well. Automakers don’t have to publish an algorithm to explain something that exists. It is as simple as tell when to expect the engagement.
The problem with this statement, is in the wording. What Rodrigues should have said is. By anticipating the POSSIBILITY of slip, it can prevent it. Just saying the system PREDICTS slip, gives the impression that it can detect an "Ice patch" on the road ahead of you, and engage the rear wheels. The system does not have ESP. Unless the "Psychic Friends Network" designed it.
and this 'press release' type of wording aggravates an already dangerous situation, folks like akirby, perhaps, that bite into this whole thing and then drive their AWD or SC equipped vehicles like madmen until, of course, he ends up in a snowbank. And you are right the computer that controls this AWD system must also know who really killed Kennedy - bet if we searched thru Ford press releases we could find the answer along with an unfulfilled promise to bring the culprit to justice.
Thanks for your consideration,
Jeannine
Jeannine Fallon
Corporate Communications
Edmunds Inc.
Where do you get that incorrect idea, impression, and opinion?
Consumer Reports and JD Powers data seem to confirm this. In Consumer Reports, the difference between below average and above average is usually less than 5 percentage points over a five year period. And JD Powers' Long Term Reliability data shows that the most reliable cars in this segment have around 2.5 problems over a 5 year period vs below average cars in this segment having around 3.7 problems. Not a big difference.
And why do you have to be so rude when you want to express yourself? I know you like Honda and their reputation for reliability despite your having to replace your transmission in your Accord. I've had two Accords so far and they have been good cars. Personally, I like Honda a lot.
But with two independent organizations coming to similar conclusions about the excellent reliability of the vast majority of cars in this segment allowed me to choose a car with traits that I prefer. For me it was having extra hauling capacity in a hatchback and superior braking performance in case emergencies crept up. I also wanted something comfortable that had a good amount of power and handling that could control this power. I wanted good safety ratings too. The Mazda6 had all these things and was several thousand dollars less than the Accord or Legacy GT that made my short list. And since I thought it looked much nicer and had more direct steering, it was an easy choice. When I first started looking, Mazda was nowhere on my cars under consideration list. But keeping an open mind about what cars I'd consider led me to my perfect choice and after nearly 2 years of ownership I couldn't be happier with my decision.
Here's another pic of my car:
That said, the system worked very well. I often tested it in slippery conditions such as on gravel or loose dirt, and on wet roads. From a dead standstill, going immediately to full WOT, the rear tires would chirp only very slightly before the front tires kicked in. I would say the system was able to detect slip, transfer power, and actually obtain additional traction all in well under one second.
I can see where this would be advantageous on a sedan as well.
It senses the steering angle, the throttle position and the engine speed. Based on various combinations of those inputs it knows if you're going straight or turning, accelerating or decelerating, etc. When it sees some combination of these conditions that could possibly cause slip (accelerating quickly, accelerating while turning, turning at high speed, etc.) it kicks some torque to the rear wheels JUST IN CASE. In addition to preventing POSSIBLE slip it also helps with handling.
I don't understand why that concept is so hard for you to understand. It's common sense.
That's because nobody in their right mind would think that a car could do such a thing in the first place and would not interpret that from the press release wording.
It works as advertised - let's move on.
Our argument is around whether Fusion’s AWD system has a bit of pro-activeness that it will engage all wheels under non-slip conditions which is something you’re suggesting. My understanding based on articles (including the one you provided) is that it is a completely reactive system.
You did claim something that would put an AWD system in the middle category:
“Slip is most likely to occur when accelerating briskly or when cornering. Doesn't mean that it will occur - just that it's possible or even likely depending the road conditions. Ford's AWD software senses one or both of those conditions and sends torque to the rear to AVOID a potential slip situation.”
The question remains, does the system being discussed do that? Does it always engage all wheels when turning, regardless of traction? Would it engage if the wheel speed sensors didn’t notice any change while considering steering angle? Those will make it more like Acura’s SH-AWD system which (while permanent) will redistribute torque by default and doesn’t wait for slippage. I haven’t seen any such claim from Ford.
Besides, virtually all AWD system use some form of yaw, speed and throttle sensors to make it work.
It sends torque to the rear BEFORE any slip is actually detected in an attempt to both prevent slip from occurring AND to improve handling. So yes, if you're accelerating around a corner it will shift torque to the rear - period. It does sound very much like Honda's SH-AWD but I don't think it's quite as sophisticated.
I've posted the relevant quotes from the press release that say EXACTLY that. If you don't understand them or choose to think they're lying then fine. End of discussion.
Because it's a bunch of marketing mumbo jumbo designed to obfuscate the fact the it's a rudimentary AWD system by today's standards.
I don't know if it is or is not, but it would seem to be clearly less rudimentary than the AWD systems offered on the Accord, Altima or Camry along with several other midsize sedans.
It seems pretty clear that the system can engage, under certain circumstances, without slip first being detected. Akirby has clearly documented that this is claimed by Ford. Those who don't believe it, I think ought to find some documentation to back-up their unsupported opinions.
And those of us who have a Ford vehicle with the new sytem, my '06 Explorer has it, have backed up that it does work in the way akirby describes.
You can feel the main drive wheels slip ever so slightly in slippery conditions before the other two get power. There's no doubt about that. However, in the case of the Explorer where you can feel the 4WD working via a slight vibration through the steering wheel when applying some throttle input, the 4WD does kick in sometimes when you never felt any slip and weren't expecting it. It also stays on for a little while until it senses that all is right with the world again and it's OK to shut down. This can happen at any time no matter what the road conditions are like. There are also no lights or indicators telling you what's going on with the system so I'm guessing in the Fusion, where you most likely don't feel the vibration the Explorer gives off, the switch is 100% transparent.
Many times I've hit the go pedal hard to take off and the 4WD has kicked on. I know that because I could feel it. The one big thing missing from that equation though is that the rear wheels never slipped at all like they might on wet, snow covered, or gravel covered roadways. You hit the gas too hard on any of those roads the rear wheels will slip just a bit before the front wheels kick on. So somehow the onboard computer saw something it didn't like about the way I was driving and felt it would help out a little. Whether I wanted it to or not.
There are a few above average midsize sedans in terms of long term reliability.
There are quite a few AVERAGE midsize sedans in terms of longterm reliability.
There are a few below average midsize sedans in regards to long term reliability.
Some of you might be OK with mediocre and below vehicles.
I'm not; I always want something that is AT LEAST above average, as a minimum.
It was stated above that Consumer Reports and JD Powers data seem to confirm this. In Consumer Reports, the difference between below average and above average is usually less than 5 percentage points over a five year period. And JD Powers' Long Term Reliability data shows that the most reliable cars in this segment have around 2.5 problems over a 5 year period vs below average cars in this segment having around 3.7 problems. Not a big difference.
Another thing I looked at is expected repair costs, based on edmunds data and my own information on the cost of extended warranties. Again there was not a big difference, the difference for most models was less than $100 per year. An operating cost difference of $5-10 per month is not something that would be a significant factor to me.
It becomes a problem when others are bashed, made fun of, and looked down upon as if they weren't educated enough to pick the car you (not you personally, but you get it, right) chose.
Now only if a Ford PR would put the words like you did. And given that it can only help market the AWD system better, I don't see a reason not to! How about this...
"If the front wheels begin to turn faster than the rear wheels, as would be the case if they were spinning on snow or ice, the two hydraulic pumps would turn at a different rate and hydraulic pressure proportional to the difference in their speeds of rotation would be generated."
Thats a marketing spin to suggest that the AWD system kicks in before the wheel spin happens. And this is from Honda's Real Time AWD system used in CR-V and Element.
Then you have many options to choose from. The new Accord is a question mark for now, but CR has given it the benefit of the doubt due to its solid history. And there's the Camry (I4 at least), Fusion, Milan, Sonata, Passat (V6), and others "above average". So quite a range of choices for different driving styles and budgets.