I'm leasing a car in the UK rated 48 mpg (Imperial). My company's European fleet policy requires cars under 6 L/100km. Does it qualify?

282.481 ÷ 48 = 5.88 L/100km. Yes — just under the 6 L/100km limit. Note that real-world consumption often runs 10–20% higher than official WLTP figures, so check the certified CO2 value separately.

Why does the UK still use mpg (Imperial) instead of switching to L/100km like the rest of Europe?

mpg (Imperial) is deeply embedded in UK driving culture. Despite metrication in most areas, consumer testing bodies like What Car? and Autocar continue to publish in mpg, and UK buyers use it as their primary benchmark. Post-Brexit, the UK is no longer bound by the EU's L/100km labelling requirement.

A US friend says his car gets 30 mpg. My UK car also gets 30 mpg. Are we equally efficient?

No — your US friend's car is actually more efficient. 30 mpg (Imperial) = 282.481 ÷ 30 = 9.42 L/100km, while 30 mpg (US) = 235.214 ÷ 30 = 7.84 L/100km. The US gallon is smaller, so 30 mpg (US) stretches further per litre than 30 mpg (Imperial). See: [mpg (Imperial) to mpg (US)](/fuel/mpg-imperial-to-mpg/).

Is there a quick mental estimate for this conversion?

A rough rule: divide 280 by mpg (Imperial) to get approximate L/100km. For example, 40 mpg → 280 ÷ 40 = 7 L/100km (actual: 7.06). Accurate enough for everyday comparisons and fuel budget planning.

MPG (Imperial) to L/100km Converter

Enter a value to instantly convert between fuel economy units.

From

Precision4 dp

1 MPG (Imperial) = 282.4809 Liters per 100km

Key Formulas

MPG (US) → Liters per 100km

L/100km = mpg × 235.215

Liters per 100km → MPG (US)

mpg = L/100km × 235.215

Km per Liter → MPG (US)

mpg = km/L × 2.35215

MPG (US) → Km per Liter

km/L = mpg × 0.425144

Formula

L/100km = 282.481 ÷ mpg (Imperial)

Bought a car in the UK and want to compare its fuel economy to European or Australian specs? The UK measures efficiency in miles per Imperial gallon, while Europe uses litres per 100 kilometres. The Imperial gallon holds 4.546 litres — about 20% more than the US gallon — so UK mpg figures are always higher than US mpg for the same vehicle. When you see a UK car claiming 50 mpg (Imperial) and a European equivalent claiming 5.8 L/100km, this conversion confirms they're very close (282.481 ÷ 50 = 5.65 L/100km). Getting this right prevents costly mismatches in fleet policy compliance and fuel budget calculations.

Source: NIST SP 811, Table B.8

Last reviewed: 2026-06-11 · see our methodology

Frequently Asked Questions

Real-World Examples

A popular UK turbodiesel rated 50 mpg (Imperial) converts to 5.65 L/100km — impressive even by European WLTP standards.

50 mpg imp = 5.65 L/100km

A UK family saloon at 35 mpg (Imperial) uses 8.1 L/100km, slightly above the European average for mainstream family cars.

35 mpg imp = 8.07 L/100km

A small UK petrol hybrid at 60 mpg (Imperial) achieves 4.7 L/100km — among the most efficient non-EV ratings on the European market.

60 mpg imp = 4.71 L/100km

A large UK petrol SUV at 25 mpg (Imperial) consumes 11.3 L/100km, heavy by European standards and typical for V6 4WD models.

25 mpg imp = 11.3 L/100km

mpg to l per 100km l per 100km to mpg kml to mpg mpg to kml

MPG (Imperial) to L/100km Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

Related Converters