Save fuel (and money) with eco-driving

Whatever you drive there are things you can do to save fuel and cut pollution. 

Regular maintenance

  • Get your car serviced regularly and ensure efficiency.
  • Always use the correct engine oil (check your handbook).
  • Under-inflated tyres will make your car use more fuel. Check your tyre pressure regularly especially before long journeys.

Before your next adventure

  • Travel light. Added weight means you’ll burn more fuel. If you don’t need it, leave it.
  • Reduce drag. Roof-racks and boxes create drag and increase fuel consumption. Pack carefully to reduce drag, or take it off.
  • Don’t idle. Idling wastes fuel. Your engine warms up quickly when you’re moving so don’t start the engine until you’re ready to leave.
  • De-icing. Scrape ice in the winter rather than relying on your car idling to warm up.
  • Plan your journey well. Getting lost wastes fuel. Check traffic news before you go too.
  • Combine short trips. Cold starts use more fuel so it pays to combine trips if you can.
  • Walk or cycle. If you’re only going a couple of miles or so, do you really need to use the car?

Driving tips

  • Smooth and steady. Drive smoothly, accelerate gently and read the road ahead to avoid unnecessary braking. Decelerate smoothly by releasing the accelerator and leaving the car in gear.
  • Keep rolling. Stopping then starting again uses more fuel than rolling.  Slow early for traffic lights or approaching a queue and you might not have to stop completely.
  • Change up earlier. Don’t labour the engine and try changing up at an engine speed of around 2,000 rpm (diesel) or 2,500 (petrol). If your car has a gear shift indicator this will tell you the optimum gear to be in.
  • Use your air-con wisely. At low speeds, air-con increases fuel consumption but at higher speeds, the effect is less noticeable. Try opening the windows around town and save the air-con for high-speed driving. Don’t leave it on all the time but remember to run it at least once a week to help keep the system in good condition.
  • Cut down on the electrics. Turn off your rear window heater, demister fan and headlights when you don’t need them.
  • Stick to the limit. Going faster uses more fuel. Drive at 70mph and you’ll use up to 9% more than at 60mph and up to 15% more than at 50mph. Taking it up to 80mph can use up to 25% more fuel than at 70mph.

Stop/Start

Unless your car has an automatic stop/start system, don’t switch off to save fuel unless your engine’s warm, you expect not to move for 3 minutes or so (at a level crossing for example) and you know you’ve got a good battery.

Cars with ‘stop/start’ have up-rated components and systems to make sure the engine only stops if it will restart:

  • Up-rated battery, starter motor and charging system.
  • Many have a second battery to help protect sensitive electronics when restarting.
  • Battery monitoring to disable stop/start if the battery is tired.
  • A control system to restart as soon as the driver presses the clutch pedal (or releases the brake pedal on an auto).
  • Monitoring of air-con, engine temperature, and electrical loads that could affect re-starting.
  • Monitoring the Diesel Particulate Filter if applicable.
  • Specially hardened engine bearings designed for a high number of engine start-ups.

Don’t coast

It used to be quite common to try to save fuel by rolling downhill out of gear but it’s not recommended as you don’t have full control:

  • You can’t suddenly accelerate out of a tricky situation.
  • You lose engine braking and risk overheating your brakes.
  • Coasting won’t save you fuel these days either.
  • Fuel and ignition systems are effectively combined and controlled by one Electronic Control Unit (ECU). When you take your foot off the accelerator the ECU cuts the fuel supply to the injectors anyway so there’s nothing to be gained by coasting.

Potential savings

If  you’ve got an onboard computer that shows miles per gallon/mpg then it’s easy to monitor potential savings: 

  • Take a note of the overall average you’re getting now.
  • Reset the computer and start recording a new average.
  • Try to compare similar periods of time (whole weeks or months say) and similar types of driving.

If you don’t have an onboard computer:

  • Fill the tank and record the mileage.
  • When you’re ready, revisit the same garage and fill the tank again to the same level.
  • Divide the total mileage since the first fill by the total number of litres used and multiply by 4.546 to get MPG.

Adapted from an original article by theaa.com.