Over 0–100 km/h, 840i Convertible G15 and Cayman 981 are neck and neck (5,52 s vs 5,57 s, no significant gap).
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 | Cayman 981 | |
|---|---|---|
| 0–100 km/h | 5,57 s | 5,52 s+0,05 s |
| 400 m standing start | 13,79 s | 13,64 s+0,15 s |
| 1,000 m standing start | 24,82 s | 24,69 s+0,13 s |
| Top speed (electronically limited) | 250 km/h | 253 km/h−3 km/h |
| Power-to-weight ratio | 5,53 kg/hp | 4,70 kg/hpbetter ratio |
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 | Cayman 981 |
|---|---|---|
| 0–30 km/h | 1,54 s | 1,38 s |
| 0–50 km/h | 2,50 s | 2,30 s |
| 0–80 km/h | 4,11 s | 4,02 stight gap |
| 0–100 km/h | 5,57 s | 5,52 stight gap |
| 0–120 km/h | 7,39 s | 7,16 s |
| 0–160 km/h | 12,34 s | 12,01 s |
| 0–200 km/h | 19,98 s | 19,90 stight gap |
| 400 m standing start | 13,79 s | 13,64 stight gap |
| 1,000 m standing start | 24,82 s | 24,69 stight gap |
| Top speed limited | 250 km/h | 253 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 | 279 hp | Aluminum block and heads |
| Torque | 289 Nm | |
| Weight | 1 310 kg | manufacturer kerb weight |
| Drivetrain | Propulsion | |
| Gearbox | 6-speed |
Off the line, the Cayman hits 100 km/h in 5.52 s versus 5.57 s for the Bmw 840i Convertible. The 0.05 s gap is negligible: both vehicles are neck and neck.
At 200 metres, the Cayman is doing 136 km/h against 136 km/h for the Bmw 840i Convertible. The gap is 0.13 s. The gap widens compared to the 0-100.
At 400 metres standing start, the Cayman crosses the line in 13.64 s versus 13.79 s. The 0.15 s gap represents roughly 7 m of track - barely a car length.
Past 400 metres, nothing changes. Same ceiling, same acceleration, same trajectory - both rivals run in formation to the line. The 0.14 s gap at 1,000 metres confirms what the specs already suggested: on track, they’re interchangeable. The real contest happens elsewhere - range, comfort, charging network reliability.
Electronically capped at 250 (i.e. 155 mph - industry threshold) km/h, the Bmw 840i Convertible never reaches its natural aerodynamic ceiling in this duel. That’s not a physical limit of the motor - it’s a deliberate manufacturer decision, typically tied to standard-fit tyre ratings or model-range positioning.
With two combustion powertrains, the difference comes down to power-to-weight ratio (5.53 kg/hp vs 4.70 kg/hp) and transmission (Automatic vs Unknown).
In European road use (130 km/h max), both vehicles reach the legal speed limit in under 8.44 seconds. The 0.05 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.
Swap one of the two models to explore an equivalent duel in the same segment.
Over 0–100 km/h, 840i Convertible G15 and Cayman 981 are neck and neck (5,52 s vs 5,57 s, no significant gap).
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. Cayman 981: 279 hp, ratio 4,70 kg/hp.
840i Convertible G15: 250 km/h. Cayman 981: 253 km/h.