I'm curious how come most newer suv's 4wd system only works at low speed. For example, my buddy's 06 Toyota Rav4's 4wd system only work under 30mph. If speed exceed's 30mph, it will automatically turn off 4wd. Also, this past weekend I test drove a 03 Honda Pilot. 4WD on the Pilot only work in the two lower gears(2 & 1). I know a driver wouldn't go over 30mph on a resident street in the snow but say you're in the highway doing about 45mph. Does this have something to do with safety or something? Or it suppose to meant that you dont need 4wd at speeds 30mph+? Save gas?
dont F&%&^$&%(*)(*)%^%$%^ remind me!!! they are 50/50 split through 1-2 I believe then 90/10 split at least on teh Foz's so I have heard
just dont forget the switch is on... or new tranny will be needed shortly... ha ah a much discussion over ont eh Forester forums about this... also I am looking at doing the e-brake one sometime...
Probably for better gas mileage. Most cute suvs of that type are fwd based anyway so there isn't a whole lot of need for 4wd at speed.
on the old ones, and AFAIK the new ones aren't really any different in design. the front pinion is mechanically connected to the clutch packs. if any wheels are going to spin, the fronts will first. then the TCU varies the pressure on the transfer clutches based on speed inputs between the front and rear speed sensors. which is why it sucks....it doesn't realize it's slipping until it's already too late. BUT, cut the power to the Duty C, and the transfer clutches lock regardless of TCU output. so they don't slip at all. also, there isn't really a NEED for 4WD at speed in anything. only thing you can do then is hold a big ol' drift (not that I don't like that). FWD is plenty to counter-steer an accidental slide.
Disgaree. Corner exits, even in the dry are much, much better with all four wheels. You'll get much higher performance with all four wheels.
All wheel drive robs power and gas mialage at higher speeds, its all a ploy by big auto to trick buyers, "35 mpg, and 4wd? I will take one" big auto is jealous of how great subys are, and that they suck, and they know it best when we do 4wheel drifts by them at 70, while thier quote "awd cars" spin into the ditches on 1/2 an inch of snow, cuz they are really 2 wheel wonders.. Long live 50/50 symetrical awd!!!!!!!:biggrin::biggrin::laugh::laugh:
Put the pipe down and read the thread. Subarus do the same thing. Big auto isn't "jealous" of Subaru. They're not some sort of wonder car that has secret technology, they use the same tech as every other car manufacturer out there. There is only one transmission in the Subaru line that uses a 50/50 split, and that's the 5MT.
I disagree with your disagreement. If one is coming anywhere near the limit that they "need" 4wd in a suv they are driving too fast for conditions, even in the dry. With the advent of stability control 4wd becomes even less important at higher speeds.
One thing about the Honda Pilot is that you only use the "VTM-4" in 1st or 2nd gear and reverse is when you are buried in deep stuff. Other it is all electronically controlled 4wd aka only the rears work when needed. And yes GAS MILEAGE.
I thought we were talking about all situtations ("anything") here. And it isn't like people haven't tracked or auto-xed a forester or OB. Yes Where the hell in my post did I say ANYTHING about the street? FFS. Perhaps you shoudl stop assuming. I've done 4 track days in the past month (and one autocross), I'm all about the closed course.
perhaps you should chill track days aren't needed at all. in ANYTHING. They're fun. I want to do them whenever I can. but certainly not needed. it's not really news that FT4WD is not true 4WD, and will not perform the same in offroad situations. it's just that SUVs are becoming more and more popular for street use, and as such, are more and more commonly being fitted with FT4WD.
it wasnt the pipe, it was a bottle, and i was having some fun, take the sarcasm and suby pride with a smile, and i rock the 5MT...
Like I said before, one wire and a switch takes care of all woes. Whether it be a yota, honduh, chevy, ford or subaru, you can lock it if you really want to.
I don't like being accused of using the public roads as my own personal track day. Track days being "needed" are a matter of debate However, i'd argue, I NEED AWD at any track day when it rains? Partially because I'm a ****ty driver and partially because all the 2WD cars seem to leave early when it rains, leaving me an empty track. I need it so I'm not wasting $100-75 (pro-rated half-track day) by leaving early becaus eit rains.
The original question was why are some newer 4wd systems not engaged at higher speeds. Aside from that the discussion was about cute suvs, not performance based vehicles.
