Poor driving lifts fuel consumption

Road testing by the AA showed avoiding poor, jerky driving can increase motorists' fuel consumption by 20 per cent.

The tests found that "non-eco" driving guzzled far more extra gas than driving with low tyre pressures (nearly eight per cent more fuel) and leaving air-conditioning on (nearly nine per cent more fuel), AA Directions magazine reports.

AA technical advice manager Jack Biddle said his team thought it was time to double check some commonly used fuel saving tips and establish which tips actually had the greatest effect on fuel consumption.

"By changing their driving style and habits, motorists can make considerable savings on their fuel costs," he said.

The AA technical advice team took three test cars, ranging from 1.6 to 2.5 litre engine sizes, on a 200km circuit around the Coromandel Peninsula, to mix easy open road motoring with steep, twisty hills and some low-speed town driving.

With each vehicle, a circuit was completed under normal conditions to set a benchmark, driving in a relatively conservative manner. They drove with the air-conditioning on, with manufacturer-recommended tyre pressures, windows closed and, in addition to the driver and passenger, carried 15kg of luggage.

Doing the circuit in one car with the air-conditioning switched off saved 8.68 per cent of fuel.

Lowering the tyre pressure on another car from the recommended 33psi (front) and 30psi (rear) to 24psi all round - "not enough to be dangerous and not enough to damage the tyres..." - used 7.76% more fuel.

Their "non-eco drive... in a manner which we often see on our roads" - accelerating hard, braking late into corners and intersections, accelerating down hills instead of letting the car's momentum do the work, and operating the throttle unevenly - used nearly 20 per cent more fuel.