Re: traction control vs quattro

[Dave Eaton <dave.eaton@minedu.govt.nz>]

..>From: "BRUCE, ERIK D.  -ERDB" <ERDB@chevron.com>
..>Date: Tue, 26 Nov 1996 10:40:00 -0800
..>
..>I think I saw some discussion about this in the archives, but I can't
..>find it now, so I'll ask anyway (sorry if I annoy!):
..>
..>At the local auto show yesterday I got into an interesting discussion
..>with the BMW rep, who tried to tell me that their traction control was
..>just as effective in snow as any 4WD system (including quattro).
..>Specifically, she said that I wouldn't need tire chains when there are
..>chain requirements.  Not sure I believe her.  (Actually, I'm sure I
..>don't.)
..>

no contest, but the propaganda from the likes of bmw, mercedes and saab
continue.

there is no way that a traction control system which subtracts power from
the driven wheels in order to maintain tyre contact can compare to an
awd system where the power is evenly proportioned over all 4 driven wheels.

scenario:
you're entering a bend and realise you're travelling too fast. 80% of drivers
will take their foot from the gas pedal at which time they are passengers in
a relatively unguided missile.  in this situation, traction control is of *no*
help to you at all, because neither of the driven wheels are actually driven.
end of story.

in this situation, with quattro, you still have 4 wheels sharing the job of 
accelerating (decelerating) the car which leaves more tyre adhesion for
the job of keeping the car on the road.  result is safer (or faster) cornering.

i've seen this demonstrated with a new bmw 740, jag sovereign and s4 entering
a wet 90 degree right turn at 100km with trailing throttle. the bmw and jag
(both with traction control) careered off the road in an abrupt (and potentially
expensive) manner.  the s4 (at the same speed) maintained it's line around the
corner without drama.

fth
-dave
'93 s2
'90 ur-q