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Home›Consumption›Porsche Boxster vs BMW 420i

Consumption comparison

Porsche Boxster S 987 vs BMW 420i Convertible G22: how much do I save per year?

Same car, two powertrains. The simulator below calculates the gap based on your mileage and charging type.

PorschePetrol

Boxster S 987

63.973429 L · 2011

10,9 L/100km

VS
BMWPetrolMost economical

420i Convertible G22

59 L · 2021

6,1 L/100km

MotorwayRange & chargingPerformance0-100, top speedConsumptionAnnual TCO

Annual mileage

15 000 km/an

5 000 km50 000 km

Simulated driving mix

Drag anywhere on the bar to adjust

Fuel price

Petrol 95 : 1,99 €/L·Diesel : 1,75 €/L

Annual energy cost · 15 000 km

Typical annual usage : Mix 30% city / 50% road / 20% motorway

PorschePetrol

Boxster S 987

Annual energy cost · 15 000 km

3 877€

25,85 € / 100 km

Equivalent to 1 948 L of petrol 95 per year

Weighted consumption
13,0 L/100km
Fuel price
1,99 €/L
Fuel used
1948,4 L per year
BMWPetrolMost economical

420i Convertible G22

Annual energy cost · 15 000 km

1 895€

12,64 € / 100 km

Equivalent to 953 L of petrol 95 per year

Weighted consumption
6,3 L/100km
Fuel price
1,99 €/L
Fuel used
952,5 L per year
Annual gap 420i Convertible vs Boxster S+1 982 €/an≈ 996 L petrol 95

BMW 420i Convertible G22 costs 1 982 €/an less in energy than Porsche Boxster S 987, over 15 000 km for this driving mix.

≈ 996 L of petrol 95 saved per year

Your savings over the ownership period

Cumulative projection by annual mileage. The cheaper-to-run vehicle widens the gap year after year.

Annual mileage

15 000 km/an

1 year

1 982 €

≈ 996 L petrol 95

3 years

5 946 €

≈ 2988 L petrol 95

5 years

9 910 €

≈ 4980 L petrol 95

10 years

19 819 €

≈ 9959 L petrol 95

Cumulative savings for BMW 420i Convertible G22 versus Porsche Boxster S 987. Excluding purchase, insurance, maintenance and depreciation.

Annual fuel cost breakdown

Projection over 15 000 km/year.

Porsche

Boxster S 987

Fuelkm/year€/kmAnnual cost
Annual fuel1,99 €/L15 000 km0,258 €/km3 877 €
BMW

420i Convertible G22

Fuelkm/year€/kmAnnual cost
Annual fuel1,99 €/L15 000 km0,126 €/km1 895 €

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Frequently asked questions

On a 100 km mixed trip, the BMW 420i Convertible is about 50% cheaper than the Porsche Boxster S with default parameters. This ratio shifts with your actual energy prices - simulate for your profile.

The BMW 420i Convertible is cheaper across all distances with default rates. If your energy prices differ significantly, simulate to see the real impact on your budget.