⚖️ Comparison · Updated for 2026

MPG vs L/100km

Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.

Quick answer: MPG measures distance per unit fuel (higher = better). L/100km measures fuel per unit distance (lower = better). They are inverse, not linear. A car going from 30 to 40 mpg saves more fuel than going from 50 to 60 mpg — the L/100km figure shows this; MPG hides it.
Decision guide — when to use which
Use MPG when…

UK, US, Canada (alongside L/100km).

Use L/100km when…

All of continental Europe, Australia, New Zealand, official EU type-approval figures.

📊 Side-by-side comparison
Aspect MPG L/100km
Higher number is Better Worse
UK 40 mpg 40 UK mpg 7.06 L/100km
UK 60 mpg 60 UK mpg 4.71 L/100km
Why L/100km is better Quick comparison difficult Linear — easy to compare improvement
Used on car spec sheets UK, US All EU, Australia, NZ

Frequently asked

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Why is L/100km better than MPG?

L/100km is linear with fuel cost. Going from 8 L/100km to 6 L/100km saves the same fuel per km as going from 6 to 4. With MPG, the equivalent jumps (e.g. 30 to 40 mpg saves more than 50 to 60 mpg) — the relationship is not intuitive.

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Is MPG dying out?

In the EU, official figures are mandated in L/100km. The UK kept MPG by tradition. Even hybrid and EV efficiency in Europe is now sometimes given in kWh/100km, following the same 'usage per 100km' logic.

Reviewed for 2026. This comparison is general guidance based on publicly available information. Prices, rates, rules and specifications change, so check current details with the provider or an official source before making a decision. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project. We don't sell SEO links or accept paid placements in this content.

Frequently asked questions

Why is L/100km better than MPG?

L/100km is linear with fuel cost. Going from 8 L/100km to 6 L/100km saves the same fuel per km as going from 6 to 4. With MPG, the equivalent jumps (e.g. 30 to 40 mpg saves more than 50 to 60 mpg) — the relationship is not intuitive.

Is MPG dying out?

In the EU, official figures are mandated in L/100km. The UK kept MPG by tradition. Even hybrid and EV efficiency in Europe is now sometimes given in kWh/100km, following the same 'usage per 100km' logic.