9 driving habits that save fuel, with the real numbers

By the TripRank team · 24 October 2026 · 8 min read

You cannot control the price of fuel, but you control how much you burn. Published guidance from the US Department of Energy's fueleconomy.gov says aggressive driving, meaning speeding, rapid acceleration and hard braking, can lower gas mileage by roughly 15% to 30% at highway speeds and 10% to 40% in stop-and-go traffic. The numbers vary by car and road, but the direction is the same everywhere: smooth is cheaper.

1. Accelerate gently

Hard starts burn fuel the engine then has to push through. Roll on the accelerator and let speed build smoothly. This is also the habit that most improves your driving score.

2. Anticipate and coast

Looking two or three cars ahead lets you lift off early and coast to a stop instead of braking hard. Every hard brake wastes energy you just spent building speed.

3. Do not speed

Mileage usually drops quickly above about 80 km/h. fueleconomy.gov estimates that slowing down by 5 to 10 mph (roughly 8 to 16 km/h) gives an average fuel economy benefit of 7% to 14%. On open roads, find your car's sweet spot, often between 80 and 90 km/h, and hold it.

4. Hold a steady speed

Constant changes between fast and slow cost fuel. Where it is safe, use cruise control, and leave a bigger gap so you are not constantly reacting.

5. Do not idle

An idling engine gets zero kilometres per litre. fueleconomy.gov notes idling can use a quarter to a half gallon of fuel per hour depending on engine size and air conditioning. If you will wait more than a minute or so, switching off is usually cheaper than idling.

6. Carry less

Extra weight costs fuel: about 1% of mileage for every 100 pounds (around 45 kg) in a typical car, and more in a small one. Empty the boot of things you do not need.

7. Keep tyres properly inflated

Under-inflated tyres increase rolling resistance. Check pressure monthly and before long trips, using the figure in your car's manual, not the number on the tyre sidewall.

8. Plan the route and combine errands

A warm engine is more efficient than a cold one, and a route with fewer stops and signals is cheaper than a shorter one with many. Combining errands into one trip saves cold starts.

9. Measure it

You improve what you measure. TripRank estimates fuel and cost for every trip and every week, using your car's mileage and the fuel price you enter, and shows your hard brakes and hard starts on the map. Change one habit for a week and watch the weekly cost and score move together. Learn more in what TripRank is, then try it free.

A simple one-week experiment

1. Drive the same commute for three days as you normally would and note the average score and cost.
2. For the next three days, apply habits 1 to 3 only.
3. Compare the weekly recap. The trend matters more than any single day.

Want a friend to try it too? Create a private crew and compare, as explained in our guide to safe competition.

Figures quoted from fueleconomy.gov (US Department of Energy). Results differ by vehicle, load, traffic and conditions.