Originally Posted By: rjundi
Originally Posted By: antonmnster
Audi Quattro.
Hands down, by FAR the best AWD. If you don't agree you're not paying attention.
I have seen it fail in certain situations although I think all the greats will in a certain condition.
One test was a Q7 vs SH AWD MDX on steep split surface(ice one side pavement other).
Another was a Q5 in a huge fail in another:
http://www.youtube.com/v/mkQ5yBnS4SU
In the end if you get to your destination it worked!
It's very easy to stack the deck against a Torsen based AWD system. Torsen differentials operate based on a torque imbalance and uses the imbalance to bias against itself. When you completely eliminate that bias (like lifting a wheel off the ground), you turn it into an open differential.
The easiest way to correct this is the most low tech: Two foot driving. When the tire comes off the ground, having your foot on the brake will slow the axle with no friction and give the Torsen some bias to work against. This is HMMWV (which use Torsen diffs front and rear) Driving 101 in the military. I would expect Audi to do this themselves though BTCS (like everybody else does), but then again, it's easy enough to simply turn traction control off to slant the test results and make it look like an inferior AWD system, if that's your agenda.
That said, it's equally easy to defeat most "high tech" AWD systems. Take out a wheel speed sensor. No more AWD.
My 2WD Chevrolet Trailblazer with its G80 locking rear differential can walk through both of the tests with no drama. No high tech AWD system needed.