4WD and the FEH
 

This is a bit of a Subaru commercial, but I like the ramp system that was used to test the AWD systems of the various vehicles:
http://www.youtube.com/watch?v=ooQRxlChvMw

Any thoughts on how the FEH AWD would perform on the ramp tests? Would it be as good as the Subaru seems to be?

NOTE:
[This is a spin-off from the end of another thread, "FEH and extreme cold climates-any issues?": https://www.greenhybrid.com/discuss/...23/index6.html ]

Re: 4WD and the FEH
 

The preachers last service was interrupted by loud alarms
http://i241.photobucket.com/albums/f...itdetector.jpg

Re: 4WD and the FEH
 

C/P from the other thread:

Hmm, good video! The FE/FEH is a asymmetric 4WD but until '09 the FEH didn't have traction control but still neither would perform as good as the Subaru which has symmetric AWD.

Being a asymmetric 4WD, you'd have the steering torque they mentioned in the video. If you have AdvanceTrac(>'09 FEH) and traction at one wheel, you could climb the ramp. Without AdvanceTrac(<'09 FEH), you can't call it AWD either, it's just 4WD!

P.S. Another meaningless post from BillyK.

Re: 4WD and the FEH
 

Interesting video. However, not real-world.

In the real world winter ice & snow driving I've experienced in my 46 driving years, I NEVER have had only the front wheels on ice, and the rear wheels on concrete! Or any one wheel on a bare surface while the other three are on ice. I mean, get real here. (That's the reason for BillyK's BS meter, which I thought was funny).

Usually the whole street is glaze ice, and all 4 wheels are spinning. That's the real world. All cars with AWD would probably do well in that situation, don't you think?

Re: 4WD and the FEH
 

Yes, not real-world but it's about time someone starting explaining the differences in the myriad of F/awd systems out there in the marketplace. So the "ramp" is a good start.

In my "real-world" I would settle for simple RWD and a set of tire chains when the going gets (d)icy. In the meantime I want NOTHING to do with Symmetrical AWD, F/awd or R/awd. I simply do not want engine "drive" of any kind, leading or lagging, on my front wheels when it is most important, becomes most important for their BASE use, directional control.

Re: 4WD and the FEH
 

I expect that within a year or two we will see the FE/FEH F/awd models with a bit of "overdrive" to the rear so that like the SH-AWD system more than 50% of the engine torque can go to the rear upon front wheelslip/spin. That way maybe the TC firmware can be made less aggressive and not leave F/awd owners "dead in the water".

Re: 4WD and the FEH
 

"...not real-world.."

Well, in at least one respect it really is "real-world".

Getting up and going from a dead stop with all four wheels on ice, or trying to start up an incline in that situation. Oftentimes having the ability to drive, firmly drive, more than 1 wheel, say 2, 3, or even 4, will make the difference.

I have had instances wherein it took all 4 tirechains to get up and going initially. But once underway, with momentum now operating in my favor, wish I could remove the chains. At least I was able to switch to RWD only "on the fly", '92 Jeep.

Re: 4WD and the FEH
 

AdvanceTrac...

My first experience with TC, Traction Control, was on a newly purchased 1992 LS400. I quickly discovered it to be a royal PITA. Even the slightest level of wheelspin, a wet plastic strip marking a crosswalk, and the rear brakes would be applied and the engine INSTANTLY dethrottled. Once TC activated then recovery, regaining control of the throttle, often took several seconds.

I did note that by ~2000 some of the RWD Lexus models had revised TC firmware. Upon wheelspin detection the brakes would still begin to be applied but engine dethrottling was delayed by a few seconds, presumably to allow the driver to "switch" to throttle "feathering" mode. Abating loss of traction on a RWD or R/awd vehicle is not nearly as critical as is a FWD or F/awd vehicle.

TC, of necessity, uses a rather simple "bang-bang" on/off servo loop process, much like ABS, and therefore does not have the "finesse" with feathering the throttle "just so" that a learned and experienced driver can have, can use, in truly slippery roadbed conditions. Other than the (sometimes) constructive use of wheelspin, that's the other advantage of being able to switch TC off.

I soon developed the habit of switching it off simultaneously with starting the engine. I don't think I would do that with TC on a FWD or F/awd vehicle, far too dangerous.

Re: 4WD and the FEH
 

I have a puddle in front of my driveway every year that freezes and a dry approach because snow is cleared. How about ruts in the street? I've seen people get stuck perpindicular to them all time.

You actually understand BillyK's pictures only posts? Not sure if that's aimed at the thread or a certain person? Can't tell because BillyK. never expalins his some of his picture stories!

Re: 4WD and the FEH
 

The TC does have a ON/OFF if you have. No switch, no TC. Many here thought that they had TC but that was cleared up in another thread.