Re: 4000 Quattro Question

[stevanov@orion.crd.ge.com (Ljubisa D. Stevanovic)]

>> >address.  First, a few years back while I was in Germany a friend of mine
 >> >who owned a Quattro coupe, would routinely lock the center differential
 >> >when driving at moderately high speeds (approx. 120-140 km/h) on a WET
 >> >autobahn.  This, he claimed, settled the car down and improved braking at
 >> >higher speeds in the wet. 
 >
 >> The car has 4 wheel brakes whether or not the center differential is locked.
 >> 4 Wheel drive, Audi's nor anyone elses, does not help braking. 
 >
 >if the center diff is locked, braking loads are redistributed over the
 >two axles, thus influencing the braking characteristics of the car.  i
 >don't know if it actually *improves* braking, but it will most
 >certainly be different over a 2wd or unlocked diff quattro.
 >

Locking the center diff will improve car's stability under braking by 
preventing an early rear axle lock-up (assuming the car has no ABS).
In ABS-equipped cars with mechanical diffs (e.g. 87 5000 TQ), locking 
of the center diff disables the ABS, which is a disadvantage in most
situations (deep snow and gravel being two exceptions).

While quattro traction gives superior grip and inspires confidence in
inclement driving conditions, car's braking is still largely determined by
the choice of tires. Use your judgement when driving the quattro in bad 
weather!

Ljubisa Stevanovic (stevanov@crd.ge.com)
87 5000 TQ