Audi S8 vs Xpeng X9: which is truly faster?

Off the line, the S8 hits 100 km/h in 3.83 s versus 3.88 s for the X9. Despite lacking instant torque, 571 hp of power compensates. The 0.05 s gap is negligible: both vehicles are neck and neck.

At 200 metres, the X9 is doing 173 km/h against 157 km/h for the S8. The gap is 0.17 s. The gap widens compared to the 0-100.

At 400 metres standing start, the X9 crosses the line in 11.34 s versus 11.81 s. The 0.47 s gap represents roughly 25 m of track - two to three car lengths.

Past 400 metres, the situation changes. The X9 maxes out at 200 km/h while the S8 keeps accelerating towards 250 (i.e. 155 mph - industry threshold) km/h. At 600 metres, the gap has dropped to 0.31 s.

Around 735 metres, both vehicles are level. This is the inversion point: the S8 overcomes its launch deficit thanks to a 50 km/h higher top speed.

At 1,000 metres, the S8 finishes in 21.26 s versus 22.13 s. The 0.87 s delta in favour of the S8 shows that top speed makes a clear difference.

Both rivals are electronically governed, but not at the same level: the S8 is capped at 250 (i.e. 155 mph - industry threshold) km/h, the X9 at 200 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 5.62 seconds. The 0.05 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.