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ABoxsterPetrolvsB420dDiesel
  • MotorwayMotorwayRange and charging
  • PerformancePerformance0-100, top speed
  • ConsumptionConsumptionYearly cost
  • SpecsBoxster · 420d

Porsche Boxster Spyder vs BMW 420d Convertible G22

Trip mapped at a glance. Charging stops visible, total duration predictable. Caralogy simulation at 130 km/h.

sports car · 2016 vs 2021 · Paris → Marseille · 775 km · 130 km/h
PorschePetrol

Boxster Spyder

375 ch · 2016

VS
BMWDieselPlus rapide

420d Convertible G22

190 ch · 2021

Simulation trip
Assumptions: 130 km/h · start réservoir plein · mild weather

Result · total trip time

APorsche Boxster Spyder

7h06charging included

1 stop · 164.81 €

Gap5 minin favour of 420d Convertible
BBMW 420d Convertible G22

7h01no stop

0 stops · 72.32 €

Paris → Marseille · 130 km/h · Caralogy simulation
MeasureBoxster Spyder420d Convertible G22Gap
Total time7h067h015 min · 420d Convertible G22
Charging stops1 stop0 stops1 stop · 420d Convertible G22
Cost of energy used164.81 €72.32 €92.49 € · 420d Convertible G22

Visualise the trip

Both vehicles drive at 130 km/h. The difference comes from charging stops.

PorschePetrol
Boxster Spyder
100%
496 km
Range
Paris
0 km · departure
Refuel 1
5 min · +49 L · 105.50 €
Marseille
775 km · Arrival 7h06
1
Stops
7h06
Duration
164.81 €
Cost of energy used
BMWDieselFastest
420d Convertible G22
100%
1372 km
Range
Paris
0 km · departure
Marseille
775 km · Arrival 7h01
0
Stops
7h01
Duration
72.32 €
Cost of energy used

The 5-minute lead of the 420d Convertible G22 does not come from driving speed, but from one fewer charging stop on this route (0 vs 1).

Both vehicles drove at 130 km/h for the entire trip. The gap is built at the stops: no stop for the 420d Convertible G22 versus 1 stop of 5 min for the Boxster Spyder.

Motorway consumption: the Caralogy methodology

The official WLTP figures (11,8 L/100km for Boxster Spyder and 4,5 L/100km for 420d Convertible G22) are measured on a mixed cycle averaging ~46 km/h. At a steady 130 km/h, aerodynamic drag weighs much more heavily - it grows with the square of speed. Caralogy calculates a motorway consumption specific to each vehicle based on its aerodynamic profile (SCx), weight and power curve - not a uniform correction factor. For this trip, the simulation yields 9,8 L/100km (Boxster Spyder) and 4,3 L/100km (420d Convertible G22). Full methodology: see the assumptions below the controls.

Energy cost breakdown for your trip Paris → Marseille

The cost per kilometre depends on the electricity rate applied to each segment - based on the energy source used at that point of the trip.

Porsche Boxster Spyder

SegmentEnergy usedDistanceConsumption€/kmCost (€)
Paris → Valence, A7fuel · 2.17 €/L496 km49 L consumed0.213 €/km105.50 €
Valence, A7 → Marseillefuel · 2.17 €/L279 km27 L consumed0.213 €/km59.31 €
Trip total164.81 €

BMW 420d Convertible G22

SegmentEnergy usedDistanceConsumption€/kmCost (€)
Paris → Marseillefuel · 2.17 €/L775 km33 L consumed0.093 €/km72.32 €
Trip total72.32 €

What produces these figures

WLTP combined consumption
11.8 L/100 km · 4.5 L/100 km
Fuel tank
54.0 L · 59 L

Compare with another vehicle

Replace one of the two with an alternative from the same segment

PorschePetrol

Boxster Spyder

375 ch · 2016

BMWDiesel

420d Convertible G22

190 ch · 2021

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S60 B4 vs 420d Convertible

Frequently asked questions

On Paris → Marseille (775 km at 130 km/h), the 420d Convertible G22 arrives in 7h01 with 0 fuel stops.

WLTP consumption does not reflect motorway reality. Aerodynamic drag grows with the square of speed, so real consumption is 15 to 25 % higher than WLTP combined. Caralogy calculates a highway consumption specific to each vehicle based on its aerodynamic profile (SCx), weight and power curve.

Total time = driving time + charging time. Driving time is calculated at an average speed of 130 km/h on the motorway (adjustable). Charging time is calculated based on the real power curve of each vehicle, respecting the optimal 10 → 80 % range and the maximum power accepted by the chargers on the route.

No. The displayed cost covers only the energy consumed during the trip: kWh × energy rate, with a mix of home charging and DC fast chargers. Battery wear is a long-term ownership cost, not a trip cost.

On this trip, the energy used costs 164.81 € (Boxster Spyder) and 72.32 € (420d Convertible G22). For reference, an equivalent BMW M340i (~9.5 L/100 km) would cost about 136 € in fuel.