How to Convert Fuel Economy Units
Convert between different fuel economy units instantly. Our converter handles MPG (US and UK), liters per 100 km, and km per liter-essential for comparing vehicle efficiency across different measurement systems.
Understanding Fuel Economy Units
Fuel economy measures how efficiently a vehicle uses fuel. The US uses miles per gallon (MPG), Europe uses liters per 100 km (L/100km), and some countries use kilometers per liter. Higher MPG or km/L means better efficiency; lower L/100km means better efficiency.
Fuel Economy Conversions
Key relationships: MPG (US) to L/100km: divide 235.21 by MPG. L/100km to MPG (US): divide 235.21 by L/100km. Note: US and UK gallons differ.
Example:
30 MPG (US) = 235.21 ÷ 30 = 7.84 L/100km. A car rated at 6 L/100km = 235.21 ÷ 6 = 39.2 MPG.
Common Use Cases
Real-world applications for this calculator
Car Shopping
Compare fuel efficiency of vehicles from different countries using different rating systems.
Trip Planning
Estimate fuel costs for road trips when traveling internationally.
Environmental Comparison
Compare the environmental impact of vehicles rated in different units.
Tips
- Quick conversion: 235 ÷ MPG = L/100km, 235 ÷ L/100km = MPG.
- UK MPG is about 20% higher than US MPG for the same efficiency.
- Real-world fuel economy is typically 10-20% worse than official ratings.
Frequently Asked Questions
How do I convert MPG to L/100km?
Divide 235.21 by the MPG value. For example, 25 MPG = 235.21 ÷ 25 = 9.4 L/100km. Remember that higher MPG means lower L/100km (better efficiency).
What is the difference between US and UK MPG?
UK gallons are larger than US gallons (4.55L vs 3.79L), so UK MPG numbers are about 20% higher than US MPG for the same vehicle. 30 US MPG ≈ 36 UK MPG.
What is good fuel economy?
In US MPG: 30+ is good, 40+ is excellent for gas cars. In L/100km: under 8 is good, under 6 is excellent. Hybrids and EVs can achieve much better numbers.
Why does Europe use L/100km instead of km/L?
L/100km makes it easier to calculate fuel costs for trips (multiply distance by consumption rate). It also makes small efficiency differences more visible in the numbers.