Calculate miles per gallon, kilometers per liter, and liters per 100 km from trip distance and fuel used.
30+ MPG is efficient for a gas car, 40+ MPG is excellent. Hybrids reach 50+ MPG. EVs use MPGe for comparison.
Driving style, speed, traffic, weather, tire pressure, and AC use all affect fuel economy. Track across multiple fill-ups for an accurate average.