Two drivers with the same car may have very different fuel consumption. The difference comes from road conditions, driving habits and vehicle condition.
First, road conditions matter most. Frequent stops and low-speed city driving increase fuel use. Steady highway driving is the most fuel-efficient.
Second, driving habits. Aggressive acceleration, hard braking and frequent lane changes push the engine into high load and waste fuel. Smooth starting, early deceleration and safe distance help save fuel.
Third, tire pressure. Low pressure increases friction and fuel consumption. Check pressure monthly.
Fourth, excess weight. Heavy items in the trunk force the engine to work harder.
Fifth, air conditioning. Using the A/C in summer increases fuel use by 1–2 liters per 100 km.
Sixth, poor vehicle condition. Carbon buildup, dirty throttle body, old spark plugs and clogged filters reduce efficiency. Regular maintenance solves most problems.
To save fuel: drive smoothly, lighten the load and maintain your car properly.