Audi Quattro uses differential locks and the Mercedes 4matic system applies brakes to the spinning wheels. ML has a similar system.

Going uphill in an ML, if you apply brakes, the vehicle may start to slide down as breaking takes precedence over traction control.

Brakes may wear quicker in the 4matic if the system is used frequently.

Audi system is more efficient but expensive.

Mercedes system is cheaper but less efficient and relies heavily on electronics.

__________________
Zafar
94 E320 58000 Miles