Understanding Fuel Economy: MPG vs. L/100km
When reading car reviews or specifications from different countries, you will encounter two very different ways of measuring fuel efficiency. One measures "distance per volume" (MPG), while the other measures "volume per distance" (L/100km). Our converter helps you bridge this gap instantly.
The Two Philosophies of Efficiency
It is not just a unit difference; it is a difference in thinking:
- MPG (Miles Per Gallon): Used in the US and UK. It answers the question: "How far can I go with one gallon of gas?" Higher numbers are better.
- L/100km (Liters per 100 Kilometers): Used in Europe, Canada, and most of the world. It answers the question: "How much fuel do I need to travel 100 km?" Lower numbers are better.
The "Gallon" Trap: US vs. UK
This is a common mistake for travelers. An Imperial Gallon (UK) is 20% larger than a US Gallon. Therefore, a car rated at 40 MPG in the UK is only doing about 33 MPG in the US. Our converter handles this automatically.
- 1 US Gallon = 3.785 Liters
- 1 UK Gallon = 4.546 Liters
- Formula (US): L/100km = 235.21 / MPG
Frequently Asked Questions (FAQ)
What is a good fuel economy score?
For a modern sedan, anything above 30 MPG (US) or below 7.8 L/100km is considered good. Hybrid vehicles often achieve 50+ MPG (below 4.7 L/100km).
Why does my dashboard show a different number?
Real-world fuel economy varies based on driving habits (aggressive acceleration burns more fuel), tire pressure, use of air conditioning, and even the weight of cargo in the car. Official ratings are tested under ideal conditions.
Disclaimer: The conversions provided are mathematical equivalents. Actual vehicle performance may vary.