Speed vs Fuel Cost Calculator: Is Driving Faster Worth It?

Compare two motorway speeds: minutes saved, extra litres and euros of fuel, cost per minute saved and CO₂, for example 110 vs 130 km/h.

Driving at 130 instead of 110 km/h: how much time and fuel?

Going from 110 to 130 km/h over 500 km saves about 42 minutes, but fuel consumption rises by about 22% in the tool's model, because air resistance grows with the square of speed. For a car using 6.5 L/100 km at 110 km/h, that means about 7 extra litres and €13, or nearly €0.30 per minute saved.

The model

Consumption is split into a fixed share (rolling resistance, engine efficiency) and an aerodynamic share proportional to the square of speed: C(v) = Cref × [(1 − p) + p × (v ÷ vref)²], where p is the aerodynamic share at the reference speed. With p = 55% at 110 km/h, consumption rises by 21.8% at 130 km/h; the other way round, slowing from 130 to 110 km/h cuts it by 17.9%.

Worked example

  • 500 km: 4 h 33 min at 110 km/h, 3 h 51 min at 130 km/h, so 42 min saved.
  • Consumption: 6.5 L/100 km at 110 km/h, 7.9 L/100 km at 130 km/h.
  • Fuel: 32.5 L versus 39.6 L, so 7.1 L and €12.76 more at €1.80/L.
  • Cost: €0.30 per minute saved, about €18 an hour.
  • CO₂: 15.6 kg more at 2.20 kg per litre of petrol (combustion), 19.1 kg including upstream emissions (2.69 kg/L).

Against official benchmarks

ADEME, the French environment agency, states that driving 10 km/h slower on the motorway saves 1 to 3 litres over 500 km, so 2 to 6 litres for 20 km/h: the 7.1 litres in the example sit slightly above that range; lower the aerodynamic share for a more streamlined car. France's Commissariat général au développement durable (CGDD) puts the theoretical saving between 130 and 110 km/h at 25%.

Limits

Real average speed stays below cruising speed, so the time actually saved is often smaller. The aerodynamic share is higher for an SUV, with a roof box or a trailer.

Sources and dates: ADEME Base Carbone, version 23.6 (data of 3 July 2025): SP95-E10 petrol 2.20 kg CO₂e/L and B7 diesel 2.49 kg/L for combustion, 2.69 and 3.10 kg/L including upstream, biofuel blend included and biogenic CO₂ excluded; ADEME guide on using less fuel (April 2026); CGDD report on low-carbon mobility (February 2022) (checked on 14/10/2026).

Frequently Asked Questions

How much time do you save driving at 130 instead of 110 km/h?

Over 100 km, driving at 130 km/h instead of 110 km/h saves about 8.4 minutes (46.2 min versus 54.5 min). Over 500 km the theoretical saving is 42 minutes, often less in practice because of traffic, tolls and breaks.

How much more fuel does a car use at 130 km/h than at 110 km/h?

In the tool's model (aerodynamic share of 55% at 110 km/h), about 22% more: 7.9 L/100 km instead of 6.5. Drag grows with the square of speed, (130 ÷ 110)² ≈ 1.40, but it is only part of total consumption. ADEME, the French environment agency (April 2026), counts 1 to 3 litres saved over 500 km for every 10 km/h less on the motorway.

What does each minute saved by driving faster cost?

With petrol at €1.80/L and a car using 6.5 L/100 km, going from 110 to 130 km/h costs about €0.30 per minute saved, close to €18 an hour. The thirstier the car, the higher that price.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

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