To answer that question, the guys from CarWow brought the trio to a rain-soaked runway and hosted a series of performance tests, starting off with two drag races.
All three cars are powered by twin-turbocharged V8 engines and produce close to 600 hp. Moreover, all feature dual-clutch transmissions and send power to all four wheels. With this in mind, the race should be quite competitive, but in this test, it was the RS6 Avant that stormed away in both drag races.
For whatever reason, the Audi’s Quattro all-wheel drive system is able to put its power to the ground much more efficiently in the wet conditions than the systems used by the BMW and Mercedes-AMG. Interestingly, the RS6 Avant has proven to be slightly slower than the M5 Competition and E 63 S in dry conditions.
The second test is a rolling race between the trio and it is a very different story, as the BMW and Mercedes-AMG E 63 S rocket away from the Audi with their transmissions set in automatic modes Last but not least is a braking test between the trio but as the presenter acknowledges, it wasn’t really a fair test as there wasn’t an even amount of water across the runway.