How to improve your fuel economy

The cost of filling up a car with fuel is often as big as the weekly shopping bill. However, while the cost of fuel itself is beyond the control of individual motorists, there are plenty of ways in which you can get improve your fuel economy and get the most out of every litre you put into the tank.

Plan your trips

  • The first and perhaps most obvious fuel-saving tip is to drive fewer miles. That may sound too obvious, but the fact is that almost every motorist throws away money simply because they didn’t plan their journey well enough.
  • Combine tasks and chores in one trip rather than making lots of separate ones.
  • Refine frequently taken routes – especially the school run or the drive to work. Less congested roads may add a few miles to your journey, but they can save you money if they help you to avoid traffic blackspots.
  • If you’ve got sat-nav, or even just a map, use it if you need to –driving around aimlessly in the vague hope of finding your destination adds on unnecessary miles.

 

Reduce your load

  • To move weight, your car needs energy. The more weight you have to move, the more energy the engine will have to generate, and the more fuel it will use to create that energy – so don’t burden your car with redundant stuff you don't need.
  • If the kids aren’t travelling, don’t take the buggy. If you’re not using external kit such roof boxes or bike racks, take them off the car. It’s not just the weight that’s a problem: the extra wind resistance these items create has a surprisingly profound effect on fuel consumption.
  • Carry a snow shovel in winter, but leave it in the garage in the summer. Store allotment tools on site if you can.

 

Choose the right car for you

  • The car-selection process is harder than it should be because ‘official’ fuel consumption figures are often quite inaccurate. Real-life driving is more demanding than the EU laboratory tests which produce the official figures. You should typically expect to get 10 to 15% less miles from a gallon than the Government figure suggests. That’s why What Car? has developed True MPG, a real-world fuel economy test that gives you a personalised average mpg figure you really can expect to achieve on UK roads. You can find the True MPG figures at whatcar.com/truempg.

 

Change your driving style

  • A smooth driving style can improve your car's fuel economy. There are several ways you can do this.
  • Keep moving by looking far ahead and anticipating obstacles. Ease off the throttle and keep the car flowing rather than speeding up and braking repeatedly.
  • Change up to a higher gear as soon as possible, but not so early that the engine is struggling at low revs. As a general guide, move up a gear at 2000rpm in a typical diesel car, and at 2500rpm in a petrol.
  • Be aware, however, that modern engines are built and tested to perform reliably at high revs. Driving exclusively at low revs can build up potentially damaging residues on valves, or clog diesel particulate filters. Occasional runs up to higher revs are actually good therapy for your car’s engine. 
  • Accelerate and brake as gently – but not as slowly – as possible. Acclerating slowly is no longer considered to be the best fuel-saving option. Apart from anything else, this technique can irritate other road users and give rise to safety considerations.
  • Although it’s not always practically possible, maintaining a steady 55-60mph cruise is the most fuel-efficient way to drive on motorways. Sticking to the speed limits generally is a good idea for your wallet; cruising at 70mph uses up to 25% less fuel than 80mph.
  • If think you’re going to be at a standstill for more than a minute, switch off the engine. Many modern cars come with automatic engine stop-start systems. These deliver good results if they’re allowed to work and are not over-ridden by the driver.
  • Switching on ‘comfort features’ such as the stereo, rear de-mister, or air-conditioning adds to your fuel bill because the engine has to work harder to generate the power that they use. Air-con systems are a lot more efficient than they used to be, but they’re still relatively power-hungry. In the UK, the standard heating/ventilation system in most cars is more than up to the job of handling most of our climate and demisting needs.
  • Bear in mind that open windows and sunroofs create drag, which puts extra strain on the engine and causes it to use more fuel.

 

Car care tips

  • Poorly maintained engines will run less efficiently and use more fuel, so it makes sense to keep up the servicing regime. Reducing mechanical inertia and friction is now at the heart of most manufacturers’ thinking. BMW’s Efficient Dynamics is a good example of how this kind of approach can result in great economy without compromising performance.
  • Dirty oil doesn’t lubricate engine parts as well as clean oil. Changing it isn't a cheap exercise nowadays, but checking and replenishing the level will maintain the quality of the oil, especially if your engine is designed to consume a little oil in everyday use. It’s the equivalent of a slow-motion oil change.
  • Under-inflated tyres create drag (as well as compromising safety), which means the engine has to work harder and use more fuel. Check them regularly and keep at the manufacturer’s recommended pressure.