Driving smoothly: Accelerating and braking quickly waste fuel.
Driving at 45-55mph. Compared to 70mph, you save 20% on fuel at 60mph and 30% at 50mph.
Changing up a gear as soon as the car is ready (without exceeding 3000 revs).
Not getting lost! 350,000 tonnes of fuel/year are wasted getting lost.
Switching your engine off if you're going to sit in a queue for over 45 seconds. (In a car in a queue you're exposed to 3 times more pollution than people cycling or walking).
Having the correct tyre pressure. Under-inflation by two bar can increase fuel consumption by 15%! Over-inflation can cause uneven wear and reduce your grip.
Having a tuned engine (this takes approx. 15 mins); correctly-aligned wheels and an efficient catalytic converter.
Opening your air vents rather than opening your windows (and sunroof).
Not using air-con. It uses on average 15% more fuel. In diesels, it can use 40% more.
Reducing weight in your car, (an empty roof rack can make you use 40% more fuel).
Selling your car and buying one which is cheaper to run! It may cost you £500 more initially, but could easily save you £1,000 per year!