Car Throttle recently took an extensive look into both systems to see which one is better, Audi’s Quattro or BMW’s xDrive all-wheel drive. It turns out, that there really isn’t an answer. Both systems are so significantly different, which each having its own pros and cons, that they’re actually better than the other at certain things.
For instance, Audi’s Quattro system is a fully mechanical system, with just some stability control interference. It uses a center Torsen (Torque-Sensing) differential, that can “sense” which axle is slipping and then lock the diff to the other axle to create power to the wheels. Once that other axle gains traction, the diff unlocks and reverts back to its normal 50/50 torque split.
This isn’t to be confused with smaller Audis’ Haldex-based all-wheel drive systems. All transverse (sideways) mounted engined Audis, such as the
Audi A3 and
Q3, actually use a Haldex-based system. This doesn’t use the Torsen diff as the proper Quattro-equipped Audis, even though it says “Quattro” on the back of the cars. Only longitudinal-engined Audis have proper Quattro.
BMW’s xDrive system works quite differently. It uses a multi-plate clutch that can vary torque between the axles. However, under normal driving conditions, the rear axle gets 100 percent of the power, as a BMW should. Even under slipping conditions, BMW’s xDrive is designed to send more power to the rear wheels if possible.
BMW' xDrive AWD vs Audi's Quattro AWD