I think Mike was right on but there's no point really arguing since different
manufacturers slap the label on different systems. The real difference boils
down to two things:
1) 4wd normally would be a system that's intended to be used only when
conditions warrant rather than left on always
2) 4wd is what hunters use. AWD is the system used on all the SUVs I see
tits up in a ditch while I drive by in my focus in a blizzard.
Mark M
In a message dated 9/17/2005 2:45:13 PM Eastern Daylight Time,
bkitterer@mac.com writes:
> This is true ONLY if the differentials are locked. For some years
> now 4WD's have had front and rear differentials that behave just like
> the two wheel drive differentials. The big difference is traction
> management where power will be transfered from the wheel that looses
> traction to the wheel that has some traction. You would only lock the
> differentials if you are in situation where you need to drive all
> wheels at the same time because none of the individual wheels can
> maintain traction. The only places that come to mind where you would
> need this is on say sheet ice, steep grades with very deep sand,
> loose rocky grades and such. Even in the deep beach sand on the east
> coast I never had to lock the differentials on my Grand Cherokee.
>
> Bob Kitterer
>
> 1960 Sprite (Mk IV in disguise)
> 1966 Sprite Mk III (Trevor, in boxes)
> 2000 Miata Special Edition
> 2002 Jeep Grand Cherokee
>
>
>
> On Sep 17, 2005, at 12:41 AM, Mike Rambour wrote:
>
> > its not as completely simple as that, although the above is true.
> > A true 4-wheel drive has problems driving on the street since the
> > front wheels travel a different distance than the rear wheel during
> > sharp turns and also unless the gears front to rear are perfectly
> > matched either the front wheels will drive harder than the rears or
> > the rear will push the front end, we are not talking about a lot
> > here, maybe 1/100th (maybe even 1/1000th I don't know) of a
> > revolution difference but that will eventually bind up the u-joints
> > and if you keep a 4-wheel drive engaged on city streets, you will
> > find that you "chatter" the tires more than normal and will wear
> > out parts much quicker as you bind the u-joints between the front
> > and the rear (hopefully you wont damage the transfer case but we
> > wont get into how I know that)
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