MPG vs L/100km: What Is the Difference?
Miles per gallon (MPG) tells you how far your vehicle can travel on one gallon of fuel. Higher is better — a car that gets 40 MPG is more efficient than one that gets 25 MPG.
Litres per 100 kilometres (L/100km) tells you how many litres of fuel your vehicle consumes to travel 100 km. Lower is better — a car that uses 6 L/100km is more efficient than one that uses 10 L/100km.
The key difference is direction. MPG is a distance-per-fuel measure (more is better). L/100km is a fuel-per-distance measure (less is better). MPG is standard in the United States; L/100km is standard in Australia, Canada, Europe, and most of the rest of the world.
How to Convert Between MPG and L/100km
The conversion formula between MPG (US) and L/100km is:
L/100km = 235.214 ÷ MPG
MPG = 235.214 ÷ L/100km
Common conversions:
- 25 MPG = 9.4 L/100km
- 30 MPG = 7.8 L/100km
- 35 MPG = 6.7 L/100km
- 40 MPG = 5.9 L/100km
- 50 MPG = 4.7 L/100km
Why L/100km Is More Intuitive for Budgeting
With L/100km, fuel cost calculations are direct. Multiply your consumption rate by the distance in hundreds of kilometres, then by the price per litre:
Fuel cost = (Distance ÷ 100) × L/100km × Price per litre
Example: a 500 km trip in a car using 8 L/100km, with fuel at $2.10/L:
(500 ÷ 100) × 8 × $2.10 = 5 × 8 × $2.10 = $84.00
What Is a Good Fuel Economy Rating in Australia?
Typical fuel consumption for common vehicle types:
- Small cars (e.g. Toyota Corolla, Mazda 3) — 5.5–7.5 L/100km
- Medium cars (e.g. Toyota Camry) — 6.5–9.0 L/100km
- SUVs and 4WDs — 8.0–14.0 L/100km
- Utes (e.g. HiLux, Ranger) — 8.5–12.0 L/100km
- Hybrids (e.g. Toyota RAV4 Hybrid) — 4.5–6.5 L/100km
These are combined cycle figures. Real-world consumption is typically 10–20% higher than manufacturer-rated figures depending on driving conditions.
How to Calculate Your Actual Fuel Economy
- Fill your tank to full. Note the odometer reading.
- Drive normally until the tank is low.
- Fill the tank again. Note the litres added and the new odometer reading.
- Calculate: L/100km = (Litres added ÷ Distance driven) × 100
Example: you fill up with 55 litres after driving 620 km:
(55 ÷ 620) × 100 = 8.9 L/100km
What Affects Fuel Economy?
- Speed — fuel consumption increases significantly above 100 km/h. Most vehicles are most efficient between 80–100 km/h
- City vs highway — stop-start city driving uses significantly more fuel than steady highway speeds
- Air conditioning — A/C adds 5–15% to fuel consumption
- Tyre pressure — underinflated tyres increase rolling resistance and fuel use
- Vehicle load — carrying heavy loads and towing increases consumption. A roof rack adds aerodynamic drag even when empty