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A718vsB420iPetrol
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  • PerformancePerformance0-100, top speed
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  • Specs718 · 420i

Porsche 718 Boxster vs BMW 420i Convertible G22: which is truly faster?

Simulated drag race 0 → 1,000 m in real time. Synchronised speed counters and stopwatch. Physics calibration on 7 manufacturer measurements.

sports car · 2018 vs 2021 · Methodology
PorschePetrolFaster

718 Boxster

300 hp · 380 Nm · 1,335 kg · 2018

VS
BMWPetrol

420i Convertible G22

184 hp · 300 Nm · 1,690 kg · 2021

Result · 0–100 km/h

APorsche 718 Boxster

4.64 s

Gap3.50 sin favour of 718 Boxster
BBMW 420i Convertible G22

8.14 s

Summary · Caralogy simulation
Measure718 Boxster420i Convertible G22Gap
0–100 km/h4.64 s8.14 s3.50 s · 718 Boxster
400 m standing start12.76 s15.97 s3.21 s · 718 Boxster
1,000 m standing start23.08 s28.97 s5.89 s · 718 Boxster
Top speed (electronically limited)274 km/h236 km/h38 km/h · 718 Boxster
Power-to-weight ratio4.45 kg/hp9.18 kg/hpbetter ratio · 718 Boxster

Watch the race

Standing-start drag race, calibrated on manufacturer splits. The gap shows at each stage.

PorschePetrol718 Boxster
Speed
0km/h
Timer
0,00s
Distance
0m
BMWPetrol420i Convertible G22
Speed
0km/h
Timer
0,00s
Distance
0m
100 m
200 m
300 m
400 m
500 m
600 m
700 m
800 m
900 m
1000 m
0m → 1000m
Gap0m

Stage-by-stage comparison

Simulated performance at each stage. Best value in bold.
Stage718 Boxster420i Convertible G22
0–30 km/h1.28 s1.81 s
0–50 km/h2.13 s3.07 s
0–80 km/h3.50 s5.69 s
0–100 km/h4.64 s8.14 s
0–120 km/h6.02 s11.24 s
0–160 km/h9.81 s20.26 s
0–200 km/h15.72 s36.93 s
400 m standing start12.76 s15.97 s
1,000 m standing start23.08 s28.97 s
Top speed274 km/h236 km/h

Parameters and assumptions

Simulation

Start
Standing, straight line
Surface
Dry asphalt, 23°C
Wind
None
Driver
1 person, 75 kg

Calibration

Splits
0–100, 0–200 manufacturer
Power curve
Real measurement (Caralogy)
VMax
Manufacturer limited
Transmission
Losses integrated in model

Physics model calibrated on manufacturer splits. The limited top speed is not the real aerodynamic top speed of the vehicles.

Under the bonnet

Manufacturer technical specifications. The power-to-weight ratio is the key physical factor in a drag race.

Porsche

718 Boxster

4,45kg/hpratio better by 4,73 kg/hp
CharacteristicValueDetail
Power300 hpB4
Torque380 Nm
Weight1 335 kgmanufacturer kerb weight
DrivetrainPropulsion
GearboxDUAL_CLUTCH
BMW

420i Convertible G22

9,18kg/hpcompensated by −355 kg
CharacteristicValueDetail
Power184 hp4 cyl
Torque300 Nm
Weight1 690 kgmanufacturer kerb weight
Drivetrain-
GearboxEight-speed Steptronic transmission

The start: 0 to 100 km/h

Off the line, the 718 Boxster hits 100 km/h in 4.65 s versus 8.14 s for the 420i Convertible. At this point, the 718 Boxster leads by 3.50 s and sits roughly 21 m ahead.

From 100 km/h to 400 metres

At 200 metres, the 718 Boxster is doing 147 km/h against 115 km/h for the 420i Convertible. The gap is 2.02 s. The challenger starts to claw back ground.

At 400 metres standing start, the 718 Boxster crosses the line in 12.76 s versus 15.96 s. The 3.21 s gap represents roughly 121 m of track - a gap visible to the naked eye.

Beyond 400 metres: top speed comes into play

Past 400 metres, the 718 Boxster continues to build its lead. At 600 metres, it runs at 204 km/h versus 161 km/h. At 1,000 metres, the 718 Boxster finishes in 23.08 s versus 28.97 s, with a 5.89 s lead.

What the numbers don’t tell you

Both rivals are electronically governed, but not at the same level: the 718 Boxster is capped at 274 km/h, the 420i Convertible at 236 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 (4.45 kg/hp vs 9.18 kg/hp) and transmission (Automatic vs Automatic).

In European road use (130 km/h max), both vehicles reach the legal speed limit in under 13.10 seconds. The 3.50 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.

Other duels you might be interested in

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Frequently asked questions

Over 0–100 km/h, 718 Boxster wins (4,64 s vs 8,14 s).

718 Boxster goes from 0 to 100 km/h in 4,64 seconds (calibrated simulation).

718 Boxster: 300 hp, ratio 4,45 kg/hp. 420i Convertible G22: 184 hp, ratio 9,18 kg/hp.

718 Boxster: 274 km/h. 420i Convertible G22: 236 km/h.