Audi S6 Avant e-tron vs BMW M850i xDrive G15: which is truly faster?

Off the line, the M850i xDrive hits 100 km/h in 3.76 s versus 4.03 s for the S6 Avant e-tron. Despite lacking instant torque, 530 hp of power compensates. At this point, the M850i xDrive leads by 0.27 s and sits roughly 1 m ahead.

At 200 metres, the M850i xDrive is doing 162 km/h against 150 km/h for the S6 Avant e-tron. The gap is 0.29 s. The gap remains stable from the start.

At 400 metres standing start, the M850i xDrive crosses the line in 11.65 s versus 12.29 s. The 0.64 s gap represents roughly 32 m of track - a gap visible to the naked eye.

Past 400 metres, the M850i xDrive continues to build its lead. At 600 metres, it runs at 226 km/h versus 206 km/h. At 1,000 metres, the M850i xDrive finishes in 20.97 s versus 22.44 s, with a 1.47 s lead. Both vehicles have similar top speeds (240 vs 250 (i.e. 155 mph - industry threshold) km/h), preventing any comeback.

Both rivals are electronically governed, but not at the same level: the S6 Avant e-tron is capped at 240 km/h, the M850i xDrive at 250 (i.e. 155 mph - industry threshold) km/h. This isn’t a physical engine limit - it’s a manufacturer choice, usually for tyre safety or homologation reasons. Neither car reaches its true aerodynamic top speed.

Instant electric torque gives an advantage off the line. The higher top speed of the combustion engine gives an advantage over longer distances. The distance at which one catches the other depends on the top speed differential.

In European road use (130 km/h max), both vehicles reach the legal speed limit in under 6.10 seconds. The 0.27 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.