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A911vsB420iPetrol
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  • Specs911 · 420i

Porsche 911 Targa 4S 991.2 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 · 2017 vs 2021 · Methodology
PorschePetrolFaster

911 Targa 4S 991.2

426 hp · 499 Nm · 1,580 kg · 2017

VS
BMWPetrol

420i Convertible G22

184 hp · 300 Nm · 1,690 kg · 2021

Result · 0–100 km/h

APorsche 911 Targa 4S 991.2

4.04 s

Gap4.10 sin favour of 911 Targa 4S
BBMW 420i Convertible G22

8.14 s

Summary · Caralogy simulation
Measure911 Targa 4S 991.2420i Convertible G22Gap
0–100 km/h4.04 s8.14 s4.10 s · 911 Targa 4S 991.2
400 m standing start12.00 s15.97 s3.97 s · 911 Targa 4S 991.2
1,000 m standing start21.58 s28.97 s7.39 s · 911 Targa 4S 991.2
Top speed (electronically limited)303 km/h236 km/h67 km/h · 911 Targa 4S 991.2
Power-to-weight ratio3.71 kg/hp9.18 kg/hpbetter ratio · 911 Targa 4S 991.2

Watch the race

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

PorschePetrol911 Targa 4S 991.2
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.
Stage911 Targa 4S 991.2420i Convertible G22
0–30 km/h1.16 s1.81 s
0–50 km/h1.93 s3.07 s
0–80 km/h3.15 s5.69 s
0–100 km/h4.04 s8.14 s
0–120 km/h5.20 s11.24 s
0–160 km/h8.16 s20.26 s
0–200 km/h12.49 s36.93 s
400 m standing start12.00 s15.97 s
1,000 m standing start21.58 s28.97 s
Top speed303 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

911 Targa 4S 991.2

3,71kg/hpratio better by 5,48 kg/hp
CharacteristicValueDetail
Power426 hpB6
Torque499 Nm
Weight1 580 kgmanufacturer kerb weight
DrivetrainIntegrale (AWD)
GearboxDUAL_CLUTCH
BMW

420i Convertible G22

9,18kg/hpcompensated by −110 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 911 Targa 4S hits 100 km/h in 4.05 s versus 8.14 s for the 420i Convertible. At this point, the 911 Targa 4S leads by 4.10 s and sits roughly 21 m ahead.

From 100 km/h to 400 metres

At 200 metres, the 911 Targa 4S is doing 158 km/h against 115 km/h for the 420i Convertible. The gap is 2.49 s. The challenger starts to claw back ground.

At 400 metres standing start, the 911 Targa 4S crosses the line in 11.99 s versus 15.96 s. The 3.97 s gap represents roughly 148 m of track - a gap visible to the naked eye.

Beyond 400 metres: top speed comes into play

Past 400 metres, the 911 Targa 4S continues to build its lead. At 600 metres, it runs at 219 km/h versus 161 km/h. At 1,000 metres, the 911 Targa 4S finishes in 21.58 s versus 28.97 s, with a 7.39 s lead.

What the numbers don’t tell you

Both rivals are electronically governed, but not at the same level: the 911 Targa 4S is capped at 303 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 (3.71 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 4.10 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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911 Targa 4S vs Z4 M40i

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A4 40 TFSI vs 420i Convertible

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911 Targa 4S vs Z4 M40i

AudiVSBMW

A5 Avant vs 420i Convertible

Frequently asked questions

Over 0–100 km/h, 911 Targa 4S 991.2 wins (4,04 s vs 8,14 s).

911 Targa 4S 991.2 goes from 0 to 100 km/h in 4,04 seconds (calibrated simulation).

911 Targa 4S 991.2: 426 hp, ratio 3,71 kg/hp. 420i Convertible G22: 184 hp, ratio 9,18 kg/hp.

911 Targa 4S 991.2: 303 km/h. 420i Convertible G22: 236 km/h.