Mercedes GLC 400 4MATIC X254 vs BMW X4 M40d G02: which is truly faster?

Off the line, the GLC 400 4MATIC hits 100 km/h in 4.34 s versus 4.81 s for the X4 M40d. The instant torque of 800 Nm from the electric motor makes the difference. At this point, the GLC 400 4MATIC leads by 0.47 s and sits roughly 2 m ahead.

At 200 metres, the GLC 400 4MATIC is doing 145 km/h against 139 km/h for the X4 M40d. The gap is 0.30 s. The challenger starts to claw back ground.

At 400 metres standing start, the GLC 400 4MATIC crosses the line in 12.66 s versus 13.13 s. The 0.47 s gap represents roughly 22 m of track - two to three car lengths.

Past 400 metres, the GLC 400 4MATIC continues to build its lead. At 600 metres, it runs at 201 km/h versus 193 km/h. At 1,000 metres, the GLC 400 4MATIC finishes in 23.35 s versus 24.04 s, with a 0.69 s lead. Despite a higher top speed (250 (i.e. 155 mph - industry threshold) km/h), the X4 M40d never recovers its launch deficit.

Both rivals are electronically governed, but not at the same level: the GLC 400 4MATIC is capped at 210 km/h, the X4 M40d 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 7.54 seconds. The 0.47 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.