MPG (UK) vs MPG (US)
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
UK car magazines, UK marketing, older UK consumer references.
US car magazines, EPA fuel economy ratings, North American marketing.
| Aspect | MPG (UK) | MPG (US) |
|---|---|---|
| Gallon size | 4.546 L (UK Imperial) | 3.785 L (US wine gallon) |
| Conversion | ×0.833 → US MPG | ×1.201 → UK MPG |
| UK 60 MPG | 60 UK MPG | 50 US MPG |
| UK 40 MPG | 40 UK MPG | 33.3 US MPG |
| Metric equivalent | L/100km (Europe) | L/100km (Europe) |
Frequently asked
Why are UK MPG figures higher than US MPG for the same car?
Pure unit difference. The UK gallon is 20% bigger than the US gallon, so the same car achieves 20% more 'miles per gallon' on the UK measure. The actual fuel economy is identical.
What's the metric way of saying this?
L/100km. Lower numbers are better (less fuel for the same distance). 50 mpg UK ≈ 33.3 mpg US ≈ 5.65 L/100km.
Frequently asked questions
Why are UK MPG figures higher than US MPG for the same car?
Pure unit difference. The UK gallon is 20% bigger than the US gallon, so the same car achieves 20% more 'miles per gallon' on the UK measure. The actual fuel economy is identical.
What's the metric way of saying this?
L/100km. Lower numbers are better (less fuel for the same distance). 50 mpg UK ≈ 33.3 mpg US ≈ 5.65 L/100km.