Lexus RX 400h and 450h

wwest

First, the ability to defog/demist the rear window is not in dispute. I don't know of any automotive manufacturewr that doesn't use HEAT exclusively for that task.

Otherwise agreed, as long as the Rh and OAT is in the range wherein the A/C can efficiently dehumidify the incoming airstream the Toyota/Lexus system will work perfectly fine. But that probability becomes less likely as the OAT declines below ~45F and impossible below about 35F.

But the real problem occurs just below that 35F point when the A/C is totally and completely disabled by design (it wouldn't be functional anyway). The only way to defog/demist the windshield beyond that point is to throw HEAT at the windshield, lots of it initially until the windshield is fully defogged and then enough hot flow afterward to maintain the windshield interior surface above the dewpoint of the cabin atmosphere.

The potential problem that I foresee is that just as, simultaneously with, the Lexus climate control switching the airflow to the footwell and windshield (presumably from dash, cooling, airflow mode) the A/C compressor is being disabled. The evaporator might be covered with condensate as a result of the previous A/C operation and now that condensate will begin to evaporate into the cold and dry incoming wintertime airflow. Super-saturated airflow that a substantial portion thereof is now headed for a COLD interior windshield surface.

mirex

I never experienced that problem in my two previous RX300s. I will look for it on my 400h when the temperature goes below 45F and 35F. Thanks for the caution.

wwest

automatic climate control.

2005 RX330 owners manual, page 246, right column.

"The "Floor/Windshield" air flow mode may be applied automatically, if the outside temperature is lowered (??) down to below 0C (32F).

This is not a malfunction. "The Floor/Windshield" air flow mode turns on the defogging and defrosting function with the purpose of cleaning(??) your front view for safe driving".

This firmware change has arisen because too many of us, all the way back to 93, were experiencing unexpected and sudden windshield fogging shortly after the A/C is automatically disabled as the outside temperature declines below ~35F.

Once the A/C is disabled it is already too late, but I guess we should give Toyota/Lexus/NipponDenso an "E" for effort. The best procedure for owners to use is to manually select the combined mode, Floor/Windshield, once it is obvious that the outside temperature has declined below ~45F. That way the interior windshield surface will be preheated in in the event the outside temperature continues to decline and the A/C become inoperative.

Actually I find that the idiot thing remaining in cooling mode, coolish and dry airflow from the dash outlets, is extremely discomforting during predominantly cool or even cold weather. I suspect no one at the corporate engineering level of any of these companies is aware of the adverse effects of radiant cooling (lack of radiant heating, actually) on the human body.

skyfish400h

The best way to stay in control of humidity and temperature is to take it into the service center and have them set the user option for Automatic Airconditioning to OFF.

That way it will not go switching inot to AUTO mode when you least expect it, and you can drive around in the snow with the AC on if you want to. It will not switch off because it thinks you are cold enough.

falconone

I had the same problem in my Audi A4.

wwest

But your Audi more likely had a fogging problem on the outside surface of the windshield during a humid day or early evening.

ronr9286t

I'm not sure if this is the best place to post this question, but it seems that this a thread on power-train. My dealer was just notified that they have been allocated 2 FWD 400h cars. In looking at the brochure, the 0-60 time is somewhat slower, the weight is lower, and the mileage is higher. I'm not too concerned about 0-60, but rather rolling acceleration (e.g., 30-70). Any thoughts on the relative merits of AWD vs. FWD (aside from the obvious off-road and snow capabilities, neither one of which is important to us)?

ronr9286t

I'm not sure if this is the best place to post this question, but it seems that this a thread on power-train. My dealer was just notified that they have been allocated 2 FWD 400h cars. In looking at the brochure, the 0-60 time is somewhat slower, the weight is lower, and the mileage is higher. I'm not too concerned about 0-60, but rather rolling acceleration (e.g., 30-70). Any thoughts on the relative merits of AWD vs. FWD (aside from the obvious off-road and snow capabilities, neither one of which is important to us)?

I know this is a duplicate message - I first posted it as a response to a previous thread)

katzjamr

If you dont care about snow, none of the 400h can go off road anyway the 2wd should be a great vehicle. The 4wd 400h is mostly front drive anyway probably 90% most of the time. I think you will find acceleration excellent in the 2wd also especially at speed. You will have the added benefit of higher gas mileage, and i think you should bargain harder on this vehicle as t he 4wd is more popular and perhaps you can get them to come down off msrp. I own a 4wd 400h with 4500 miles and its an incredible car, i seriously think you should go for the 2wd if it is optioned the way u want.

rcf8000

Since when is there such a thing as a 2wd RX400h?

katzjamr

There is a 2wd Highlander Hybrid that is of course the same drive train, so i guess they slipped some 2wd 400h thru too. 90% of the time you are driving on front wheels in the 400h anyway. There is no driveline, only an electric motor in the back to drive the rear wheels. I would bet money that unless u were slipping on snow you could not tell the difference between the 2wd and 4wd models.

ronr9286t

Well, the only option not on the FWDs that are coming in is the heated seats that we find so comfortable in out current cars. I don';t want the rear entertainment system and I'm indifferent about the premium sound.

My concern about the FWD model is that the rear electric motors are missing, thereby lowering the total torque and horse-power available.

The other concern is resale value.

katzjamr

there is only one rear motor that would be missing, resale is a good question, and usually the heated seats are tied into rainsensing wipers as an option together, does that mean no rain sensing wipers on your 2wd also? How much below msrp will they go. Navigation is becoming important for resale whether you use it or not, people will be looking for it more and more on vehicles.

ronr9286t

I'm told that navigation is included, and I assume that the rain-sensing wipers would not be included.

I'm waiting for verification on the price differential between the AWD and the FWD.

Another consideration is that while we have no snow or desire to go off-road, we do live in a town in Northern CA with steep hills and we have a very steep driveway. While all are paved and I don't anticipate problems getting up the driveway with FWD, the few times I've driven up the drive with AWD (Mercedes M Class service loaner), the trip up the drive is with little or no wheel-slip.

wwest

That the AWD GS300, the AWD IS300, and the new 4runner 4WD ALL reduce the engine torque level to the front wheels during stearing inputs/changes or as a result of the yaw sensor indication that directional control is threatened.

From the horses mouth news that FWD and front torque biased AWD can be hazardous.

katzjamr

I have verified in another forum that production has started in Japan on the 2wd 400h. It will be about $1500 less msrp, and for the first time include a wood trim option if you order the Ivory interior, you can get birdseye maple. This is a $385 option.

falconone

How is that hazardous? Can it cause an accident?

wwest

it is extremely desirable to have the entire traction coefficient, or a major portion thereof, of the front tires allocated to maintaining directional control. To my knowledge there is currently no FWD nor front biased AWD that can do that, dynamically or otherwise.

Apparently Toyota is using the yaw sensor in these vehicles to dynamically allocate engine torque F/R.

Nice to know that some manufacturer is finally acknowledging the horrible fallacy of FWD being safer on adverse roadbed conditions.

Next thing we know they'll be disabling ABS unless the VSC system indicates that loss of directional control is threatened.

One can hope.

larsb

http://www.autoweek.com/news.cms?newsId=103567

Car News briefs: Lexus adds fwd version of 400h hybrid;
Posted Date: 11/8/05

Lexus is expanding the RX 400h family with a front-wheel-drive version. The front-drive RX 400h will have a base price of $45,355 when it reaches showrooms in late December, Lexus said Monday.

Since its launch in April, the hybrid powertrain RX 400h has been equipped only with all-wheel drive.

Lexus also said it is cutting the base price of the awd version by $2,350 to $46,755. The price cut is the result of making the now-standard navigation system with rear vision camera optional equipment. The change takes effect with vehicles produced this month.

The RX 400h mates an electric motor with a 3.3-liter V-6 engine rated at 268 hp. Lexus says the vehicle gets 28 mpg in highway driving conditions and 33 mpg in the city.

Prices include $695 shipping. -GREG MIGLIORE

calidave

Help me out. I want to buy a 400H but I am being told "Dude, that is a soccer mom's car - are you having the operation before or after you start wearing a skirt?"

seriously

I believe the car is gender-neutral, which is fine with me, but am I going to discover I am the only guy driving one? I do know that I am not man enough to own a VW Bug convertible. No offense to those of you who do have sufficient comfort in your sexuality.

:-)

I want a 2006 400H, with no rear entertainment system.

I want to drive a vehicle that has good environmental credibility, but that is also fun to drive. And I don't see the advantage in the Accord hybrid that I do in the 400H (though the 400H is admittedly much more expensive than the Accord H). I want the 400H so that when my San Francisco friends harass me when I pull up in my SUV, I can put them in their place by saying "Yo, it's a hybrid."

or maybe I should just punt and buy a Saturn Sky (roadster). People will assume I am getting good mileage in that.

gagrice

Have you tried out the Highlander Hybrid? I don't think there is a consensus on either one being gender specific. Though supposedly the demographics on the Prius are about 70% female. Drive what you like best. I would be more inclined to buy the Highlander for the added room and it looks more like an SUV.

larsb

http://tinyurl.com/d5d6w

Gary, I dont know where you read or heard that 70% Prius female stat, but that's incorrect.....

calidave

Most of the Prius owners around these parts are men, but I live around A LOT of engineers (mostly males, and more likely to buy a Prius than a non-engineer, I believe)

I don't think the Highlander will be as much fun to drive as the 400H. Nor is it as good looking. But that's just my perspective.

katzjamr

i think the 400h looks more masculine than the rx 330. Get it in flint mica with a grey or black interior, it will put a smile on your face, once your friends drive it they wont even notice the middle console has a space big enough for a purse LOL, just kidding, love mine, would do it all over again.

gagrice

I did not find the specific 70% figure. Only that it is higher for female than male.

They have higher income, much higher than the average car buyer—approximately $100,000 a year versus $85,000 a year for the average buyer.
They’re more likely to be female.
Hybrid drivers are a few years older than the average car buyer—closer to fifty rather than the average age of forty.
California strongly outpaces all other states

http://www.hybridcars.com/hybrid-driver-profile.html

calidave

that's not a purse

that's a ManBag

Flint Mica? I was hoping to find one in yellow.

gagrice

I like the Bamboo Pearl, is that too feminine?

calidave

I actually like the Bamboo Pearl, though I think it works best on a big sedan

and, yes, it is too feminine

briegel

I like Bamboo Pearl and Savannah Metallic and don't think they are too feminine!

PF_Flyer

I've taken down the stretch of posts here that went off in a direction that we really don't need to go.

Let's leave the cruder sexual references out of the converstation here please. Thanks.

PF Flyer
Host
News & Views, Wagons, & Hybrid Vehicles

wwest

available at the rear but that should result in a highly significant advantage over that AWD RX330. Natively the RX330 has no "driving", acceleration, torque at the rear wheels (all three diff'ls are of the open type). For the RX330 to have a significant level of torque on adverse roadbed conditions to the rear both front tires must exhibit slippage or wheelspin. At that point braking will be applied to the front so as to route engine torque predominantly to the rear.

But at the same time the engine will be dethrottled to prevent further wheelspin at the front thereby radically reducing the level of engine torque to the rear.

avery1

I have read and appreciated many of your posts in the past but I am really interested in people with actual experience with the car.

calidave

just as with the 330, the 400H will be lousy in the snow unless you put on decent tires.

I'm not sure anyone has had one in the snow, yet, as the 400H was introduced after the last spring snowfalls

wwest

I'm thinking seriously about buying a new RX400h but providing an alternative charging method for the hybrid batteries.

Attach a tag-along, swivel-(single)wheel trailer with a 5KW Honda inverter style genset to continuously charge the hybrid batteries.

Any thoughts, encouragement?

schan1w

In the Lexus literature, it says the 330 has a full time AWD system while the 400h has a part time AWD system. I udnerstand the difference between part time and full time 4WD, but never heard of full time vs part time AWD. Can anyone shed any light? Thanks.

wwest

The only "solid" drive coupling to the rear wheels was in the firmware programmer's head. It is my understanding that variable frequency AC power is not provided to the rear drive motor except at startup, hard acceleration, or at other times if the front wheels slip freely due to loss of drive traction.

avery1

Still don't have a clear picture of whether or not the 400X is actually better in snow than the 330. Anyone out there have experience with both cars? Thanks.

PF_Flyer

Which of the following best describes why you own a hybrid?

a) to make a statement

b) for the tax credit and other perks

c) because they’re environmentally friendly

d) to save money at the pump

e) to be the first to own new technology

Please submit a few sentences to support your response no later than Friday, January 27, 2006. Be sure to include your Forums username. Thanks! (wclarke@edmunds.com)

krellu

b and d. But savings at the pump is not nearly what I thought it would be.

bvend

A high performance suv that has Superior driveability in urban conditions(stop and go traffic), excellent build quality and built by a company that has earned their reputation for reliability.

mkkid

c,d,e for any hybrid, but for 400h, it's the quality, performance and company reputation. All hybids are not equal; I believe Lexus is best and wouldn't hesitate to buy another one!

mkkid

This site used to get several postings daily; now its down to several a month. What has happened?

cyclone4

Interest in this site has declined because everything is now known about this great vehicle. There is really nothing new to report. Activity in this site will probably pick up again later this year when the 2007 RX400h is released.

ighal

My dealer offers the armor teflon finish for my new RX 400h. Have to decide before I pick up the car within a couple of days. Is it really worth $399 ? The dealer says it eliminates waxing for 5Y and gives a 5Y warranty. Any opinions on how useful it is vs waxing ?

mkkid

Guess every dealer has something like this. I bought a AutoMate pkg which is a sealer/wax finish applied twice a year for 5 years. Looks fantastic each time had done (twice now). Treatment also includes dash which I'd advise against (too shiny). My cost was $500.

bgard

Dealer specs show a requirement for the 400RXh for premium fuel -- 91 octane. Is that correct?

varix

i thought that premium gas was to achieve "optimal" performance as per specs but was not required...

cyclone4

Premium fuel is definitely not required for the RX400h. It runs on 87 octane just fine. Since Ethanol (89 Octane) is readily available where we live and also 10 cents per gallon cheaper than regular unleaded, we have been filling up with the Ethanol.

By the way, I have experimented using premium and I have not found any real difference in gas mileage. So why pay 20 cents per gallon more (for premium over ethanol)? Where did you get the idea that the RX400h requires premium gas?

wwest

that if you allow your A/C to operate during the colder weather (as it normally will) it takes even a greater level, amount, of heated engine coolant to reheat the incoming airflow to your comfort level.

wwest

The RX400h uses DBW(e-throttle), BBW, Brake By Wire, and EPS, Electric Power Stearing.

The EPS via "cooperative control", is integrated with VSC and will therefore actively RESIST turning the stearing wheel in a direction that would lead to exacerbating a VSC activation circumstance. EPS will also actually RESIST turning the stearing wheel at all during hard acceleration.

I would whole-heartedly recommend that anyone considering an RX400h or HH purchase subscribe to [url=http://techinfo.toyota.com]http://techinfo.toyota.com[/url] and read up on the VDIM sections thoroughly