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  • SpecsBoxster · 420i

Porsche Boxster Spyder 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 · 2016 vs 2021 · Methodology
PorschePetrolFaster

Boxster Spyder

375 hp · 420 Nm · 1,315 kg · 2016

VS
BMWPetrol

420i Convertible G22

184 hp · 300 Nm · 1,690 kg · 2021

Result · 0–100 km/h

APorsche Boxster Spyder

4.58 s

Gap3.56 sin favour of Boxster Spyder
BBMW 420i Convertible G22

8.14 s

Summary · Caralogy simulation
MeasureBoxster Spyder420i Convertible G22Gap
0–100 km/h4.58 s8.14 s3.56 s · Boxster Spyder
400 m standing start12.41 s15.97 s3.56 s · Boxster Spyder
1,000 m standing start22.16 s28.97 s6.81 s · Boxster Spyder
Top speed (electronically limited)288 km/h236 km/h52 km/h · Boxster Spyder
Power-to-weight ratio3.51 kg/hp9.18 kg/hpbetter ratio · Boxster Spyder

Watch the race

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

PorschePetrolBoxster Spyder
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.
StageBoxster Spyder420i Convertible G22
0–30 km/h1.26 s1.81 s
0–50 km/h2.11 s3.07 s
0–80 km/h3.65 s5.69 s
0–100 km/h4.58 s8.14 s
0–120 km/h5.62 s11.24 s
0–160 km/h8.74 s20.26 s
0–200 km/h13.32 s36.93 s
400 m standing start12.41 s15.97 s
1,000 m standing start22.16 s28.97 s
Top speed288 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

Boxster Spyder

3,51kg/hpratio better by 5,68 kg/hp
CharacteristicValueDetail
Power375 hpB6
Torque420 Nm
Weight1 315 kgmanufacturer kerb weight
DrivetrainPropulsion
GearboxMANUAL
BMW

420i Convertible G22

9,18kg/hpcompensated by −375 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 Boxster Spyder hits 100 km/h in 4.59 s versus 8.14 s for the 420i Convertible. At this point, the Boxster Spyder leads by 3.56 s and sits roughly 20 m ahead.

From 100 km/h to 400 metres

At 200 metres, the Boxster Spyder is doing 154 km/h against 115 km/h for the 420i Convertible. The gap is 2.14 s. The challenger starts to claw back ground.

At 400 metres standing start, the Boxster Spyder crosses the line in 12.41 s versus 15.96 s. The 3.56 s gap represents roughly 134 m of track - a gap visible to the naked eye.

Beyond 400 metres: top speed comes into play

Past 400 metres, the Boxster Spyder continues to build its lead. At 600 metres, it runs at 216 km/h versus 161 km/h. At 1,000 metres, the Boxster Spyder finishes in 22.15 s versus 28.97 s, with a 6.81 s lead.

What the numbers don’t tell you

Electronically capped at 236 km/h, the 420i 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 (3.51 kg/hp vs 9.18 kg/hp) and transmission (Manual vs Automatic).

In European road use (130 km/h max), both vehicles reach the legal speed limit in under 13.10 seconds. The 3.56 s difference in 0 to 100 km/h is mostly felt in motorway merging and overtaking.

Other duels you might be interested in

PorscheVSBMW

Boxster Spyder vs Z4 M40i

AudiVSBMW

A4 40 TFSI vs 420i Convertible

PorscheVSBMW

Boxster Spyder vs Z4 M40i

AudiVSBMW

A5 Avant vs 420i Convertible

Frequently asked questions

Over 0–100 km/h, Boxster Spyder wins (4,58 s vs 8,14 s).

Boxster Spyder goes from 0 to 100 km/h in 4,58 seconds (calibrated simulation).

Boxster Spyder: 375 hp, ratio 3,51 kg/hp. 420i Convertible G22: 184 hp, ratio 9,18 kg/hp.

Boxster Spyder: 288 km/h. 420i Convertible G22: 236 km/h.