Question 1

Why do different countries use opposite measures?

Accepted Answer

Europe and Russia use L/100 km, where lower is better. The US uses miles per gallon, where higher is better — the logic is reversed. To convert, mpg (US) = 235.215 / (L/100 km). The common mistake is thinking more mpg is worse; it is not — more mpg means a more efficient car.

Question 2

What counts as good fuel economy?

Accepted Answer

For a petrol car, 6–9 L/100 km is good, 10–12 average, and over 14 thirsty. A diesel managing 4–6 L/100 km is good. A Toyota Prius hybrid sits around 4.5 L/100 km, an SUV 10–14, and an EV uses 15–25 kWh/100 km instead of fuel.

Question 3

How do I measure real-world consumption?

Accepted Answer

Use the full-tank method: fill up, reset the trip odometer, drive, then fill up again. Consumption = (litres added at the second fill) / (km driven) × 100. This is more accurate than the trip computer, which tends to read low. Test in different conditions — city versus highway.

Question 4

How does speed affect consumption?

Accepted Answer

Most cars are most efficient at 80–100 km/h. At 120 km/h consumption rises 20–30% versus 90 km/h, because aerodynamic drag grows with the square of speed. In stop-start city driving around 60 km/h it can jump 50–100% due to repeated acceleration.

Question 5

What is "eco mode" on a hybrid?

Accepted Answer

A Toyota hybrid runs the petrol engine above about 70 km/h and switches to pure electric below 50 km/h in town, while regenerative braking recharges the battery. It shines in the city; above 110 km/h on the motorway the advantage fades and consumption matches a conventional car.

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