Guide
How to use less fuel
Most fuel saving tips are either tiny or nonsense. Here are the handful that genuinely cut what you spend, in rough order of how much they save, ending with the biggest lever of all.
You can cut your fuel bill in two ways, by using less fuel and by paying less for it. Most advice focuses on the first and ignores the second, which is a mistake, because where you fill up usually saves more than how you drive. Still, your right foot matters, so here are the habits that genuinely work, roughly in order of how much they save, with the honest note that the single biggest saving comes last.
Ease off the speed
This is the big one for driving. Wind resistance climbs steeply with speed, so a car cruising at 70 on the motorway can use noticeably more fuel than the same car at 60, often in the region of a tenth more or worse. You do not have to crawl. Simply settling at 65 or 68 rather than nudging 80 can take a real chunk off a long journey, and costs you only a few minutes.
Drive smoothly and read the road
Hard acceleration and late braking throw fuel away, because every sharp press of the throttle is energy you then scrub off with the brakes. Looking well ahead, easing off early for lights and junctions, and accelerating gently gets you to the same places using less. In stop start traffic this smooth style is where the biggest everyday gains hide. If your car shows instant miles per gallon, watch it for a week and your foot will teach itself.
Check your tyres
Underinflated tyres drag, and drag costs fuel. Tyres down by a quarter of their proper pressure can add a few percent to your consumption, as well as wearing out faster and handling worse. Check them cold once a month and before long trips, and set them to the figure in the handbook or inside the fuel flap. It takes five minutes and it is free.
Lose the weight and the drag
A car carries whatever you leave in it, and extra weight means extra fuel, so clear the boot of the stuff that has lived there for months. The bigger culprit is drag. An empty roof rack or roof box can add a surprising amount to motorway consumption because it wrecks the airflow over the car, so take it off when you are not using it. A roof box left on all year is one of the most expensive habits going.
Cut the dead running
Idling burns fuel to go nowhere, so if you are parked up waiting for more than a minute or two, switch off. Combine short trips into one while the engine is warm, because a cold engine is least efficient in its first few miles. And use air conditioning sensibly, it does draw a little fuel, though at motorway speed open windows cause enough drag that the air con is often the better choice.
The habit that saves the most
Here is the honest part. Drive perfectly and you might trim ten to fifteen percent off your consumption, which is well worth having. But the price gap between a cheap forecourt and a dear one near you is often larger than that, every single fill, for no effort at all. The single most effective fuel saving habit is simply buying at the right place. Put your postcode into the price finder to see the cheapest forecourts within five miles, or set a free alert so you always fill up at the low point rather than the high one.
Common questions
What is the best way to use less fuel?
Ease off your top speed, drive smoothly by looking ahead and braking gently, keep your tyres at the right pressure, and remove roof boxes and dead weight. Together these can cut consumption by ten to fifteen percent. The biggest saving of all, though, is simply buying fuel at a cheaper forecourt.
Does driving slower really save fuel?
Yes, on faster roads. Wind resistance rises steeply with speed, so cruising at 65 to 68 rather than near 80 on the motorway can save roughly a tenth of your fuel on a long run, for the cost of only a few extra minutes.
Do under inflated tyres use more fuel?
Yes. Tyres low on pressure drag and can add a few percent to your fuel use, as well as wearing faster. Check them cold about once a month and set them to the figure in the handbook or the fuel flap.
Does a roof box or roof rack increase fuel use?
Noticeably, yes, especially at motorway speed, because it spoils the airflow over the car. An empty roof box or rack left on all year is one of the most expensive habits there is, so take it off when you are not using it.