Porsche 911 Carrera 4S Cabriolet 991.2 vs Bmw X4 M40i G02 : which one is faster?
0-100 km/h, 400 m, 1000 m, top speed — physics simulation calibrated on 7 measures.
Simulation de performance
Race simulation at real speed
CONFIDENCE 93%Calibrated physics simulation: SCx via VMax, power curves, Crr via WLTP, drivetrain losses. Manufacturer 0-100 is the calibration target. Confidence 93 %.
911 Carrera 4S Cabriolet vs Bmw X4 M40i: chronicle of a drag race at 303 km/h
The launch: 0 to 100 km/h
Off the line, the 911 Carrera 4S Cabriolet hits 100 km/h in 4.05 s versus 4.75 s for the Bmw X4 M40i. At this point, the 911 Carrera 4S Cabriolet leads by 0.70 s and sits roughly 4 m ahead.
From 100 km/h to 400 metres
At 200 metres, the 911 Carrera 4S Cabriolet is doing 158 km/h against 142 km/h for the Bmw X4 M40i. The gap is 0.56 s. The challenger starts to claw back ground.
At 400 metres standing start, the 911 Carrera 4S Cabriolet crosses the line in 11.98 s versus 12.98 s. The 1.01 s gap represents roughly 48 m of track — a gap visible to the naked eye.
Beyond 400 metres: top speed comes into play
Past 400 metres, the 911 Carrera 4S Cabriolet continues to build its lead. At 600 metres, it runs at 220 km/h versus 198 km/h. At 1,000 metres, the 911 Carrera 4S Cabriolet finishes in 21.53 s versus 23.62 s, with a 2.09 s lead.
What the numbers don’t tell you
Both rivals are electronically governed, but not at the same level: the 911 Carrera 4S Cabriolet is capped at 303 km/h, the Bmw X4 M40i at 250 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.
With two combustion powertrains, the difference comes down to power-to-weight ratio (3.66 kg/hp vs 5.18 kg/hp) and transmission (Automatic vs Automatic).
In European road use (130 km/h max), both vehicles reach the legal speed limit in under 7.22 seconds. The 0.70 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.
Porsche 911 Carrera 4S Cabriolet has a clear edge over the Bmw X4 M40i to 100 km/h. This difference is clearly noticeable in spirited driving and widens on standing starts.