Gal/100 Mi (UK) to L/100 Km

1 gallon (imperial) per 100 miles equals 2.824809363 liters per 100 kilometers (rounded).

How to convert gallons (imperial) per 100 miles to liters per 100 kilometers

To convert gallons (imperial) per 100 miles to liters per 100 kilometers, multiply the number of gallons (imperial) per 100 miles by 2.824809363. The factor is rounded to 10 significant digits. To go the other way, multiply liters per 100 kilometers by 0.3540061899 (rounded).

liters per 100 kilometers = gallons (imperial) per 100 miles × 2.824809363

Example: 10 gallons (imperial) per 100 miles = 28.24809363 liters per 100 kilometers.

Miles per gallon rises as a car gets more efficient, while liters per 100 km falls. The conversion between them is a reciprocal (for US mpg: L/100 km = 235.215 ÷ mpg).

About these units

Gallon (imperial) Per 100 Miles (gal/100 mi (UK))

Imperial (British)Current unit

Imperial gallons used per 100 miles.

Most fuel-economy figures rise when a car gets better, which is why miles per gallon can mislead: going from 10 to 20 miles per gallon saves far more fuel than going from 50 to 60. Quoting consumption per fixed distance avoids that trap, and the United States adopted the idea on its fuel-economy window stickers, which show US gallons per 100 miles. Using imperial gallons of 4.54609 liters gives a British-flavored variant of the same idea, equivalent in spirit to liters per 100 kilometers.

Because lower numbers mean better efficiency, the relationship with distance-per-volume units is a reciprocal. In this converter, kilometers per liter equals 35.4006 divided by the number of imperial gallons per 100 miles, since 100 miles is 160.9344 kilometers and a gallon is 4.54609 liters. For example, 5 gallons per 100 miles is about 7.08 kilometers per liter, or 20 miles per imperial gallon. The unit is rare in practice, and the British continue to rely on miles per imperial gallon alongside liters per 100 kilometers.

1 gallon (imperial) per 100 miles = 35.40061899 kilometers per liter (approximately).

Sources: Wikipedia: Fuel economy in automobiles; NIST SP 811, Appendix B.8 conversion factors

Liter Per 100 Kilometers (L/100 km)

Metric (SI)Current unit

Fuel used to travel 100 kilometers. The standard fuel-economy unit in Europe, Canada, Australia and China; lower is better.

Where miles per gallon asks how far you go, litres per 100 km asks how much you burn. Consumption is the reciprocal of economy, so it behaves linearly: if two cars each drive 100 km, the one that uses 8 litres instead of 10 saves exactly 2 litres, whatever the starting point. The sources I found do not name an inventor or date for the unit, but it is the standard in much of Europe, Africa, Australia, New Zealand, Canada and China.

Lower is better, which surprises people used to mpg. The relationship between the two scales is a reciprocal: for US mpg, L/100 km equals 235.215 divided by mpg. The Smart Fortwo cdi at about 3.4 L/100 km works out to roughly 69 mpg (US), while a full-size SUV in the US averages around 16 mpg on the highway, which is about 14.7 L/100 km. The US EPA introduced gallons per 100 miles, which carries the same logic, to counter the MPG illusion and make comparisons fairer.

1 liter per 100 kilometers = 100 kilometers per liter (exactly).

Sources: Wikipedia: Fuel economy in automobiles; fueleconomy.gov: Learn more about the gasoline label

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