Over 0–100 km/h, 840i Convertible G15 wins (5,57 s vs 7,44 s).
Performance comparison
Simulated drag race 0 → 1,000 m in real time. Synchronised speed counters and stopwatch. Physics calibration on 7 manufacturer measurements.
Simulation
Calibration
Physics model calibrated on manufacturer splits. The limited top speed is not the real aerodynamic top speed of the vehicles.
| 840i Convertible G15 | 420i F32 | |
|---|---|---|
| 0–100 km/h | 5,57 s−1,87 s | 7,44 s |
| 400 m standing start | 13,79 s−1,59 s | 15,38 s |
| 1,000 m standing start | 24,82 s−3,41 s | 28,23 s |
| Top speed (electronically limited) | 250 km/h+12 km/h | 238 km/h |
| Power-to-weight ratio | 5,53 kg/hpbetter ratio | 8,29 kg/hp |
Standing-start drag race, calibrated on manufacturer splits. The gap shows at each stage.
Simulated performance at each stage. Winner in green.
| Palier | 840i Convertible G15 | 420i F32 |
|---|---|---|
| 0–30 km/h | 1,54 s | 1,42 stight gap |
| 0–50 km/h | 2,50 s | 2,53 stight gap |
| 0–80 km/h | 4,11 s | 5,09 s |
| 0–100 km/h | 5,57 s | 7,44 s |
| 0–120 km/h | 7,39 s | 10,39 s |
| 0–160 km/h | 12,34 s | 19,05 s |
| 0–200 km/h | 19,98 s | 35,17 s |
| 400 m standing start | 13,79 s | 15,38 s |
| 1,000 m standing start | 24,82 s | 28,23 s |
| Top speed limited | 250 km/h | 238 km/h |
Manufacturer technical specifications. The power-to-weight ratio is the key physical factor in a drag race.
| Characteristic | Value | Detail |
|---|---|---|
| Power | 333 hp | 6 cyl |
| Torque | 500 Nm | |
| Weight | 1 840 kg | manufacturer kerb weight |
| Drivetrain | - | |
| Gearbox | 8-speed Steptronic |
| Characteristic | Value | Detail |
|---|---|---|
| Power | 184 hp | 4 cyl |
| Torque | 300 Nm | |
| Weight | 1 525 kg | manufacturer kerb weight |
| Drivetrain | - | |
| Gearbox | Eight-speed Steptronic transmission |
Off the line, the Bmw 840i Convertible hits 100 km/h in 5.57 s versus 7.44 s for the Bmw 420i. At this point, the Bmw 840i Convertible leads by 1.87 s and sits roughly 7 m ahead.
At 200 metres, the Bmw 840i Convertible is doing 136 km/h against 117 km/h for the Bmw 420i. The gap is 0.84 s. The challenger starts to claw back ground.
At 400 metres standing start, the Bmw 840i Convertible crosses the line in 13.79 s versus 15.38 s. The 1.59 s gap represents roughly 63 m of track - a gap visible to the naked eye.
Past 400 metres, the Bmw 840i Convertible continues to build its lead. At 600 metres, it runs at 190 km/h versus 163 km/h. At 1,000 metres, the Bmw 840i Convertible finishes in 24.82 s versus 28.23 s, with a 3.41 s lead. Both vehicles have similar top speeds (250 (i.e. 155 mph - industry threshold) vs 238 km/h), preventing any comeback.
Both rivals are electronically governed, but not at the same level: the Bmw 840i Convertible is capped at 250 (i.e. 155 mph - industry threshold) km/h, the Bmw 420i at 240 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 (5.53 kg/hp vs 8.29 kg/hp) and transmission (Automatic vs Automatic).
In European road use (130 km/h max), both vehicles reach the legal speed limit in under 12.15 seconds. The 1.87 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.
Over 0–100 km/h, 840i Convertible G15 wins (5,57 s vs 7,44 s).
840i Convertible G15 goes from 0 to 100 km/h in 5,57 seconds (calibrated simulation).
840i Convertible G15: 333 hp, ratio 5,53 kg/hp. 420i F32: 184 hp, ratio 8,29 kg/hp.
840i Convertible G15: 250 km/h. 420i F32: 238 km/h.