Inefficient driving is costing English motorists almost £7 billion in wasted fuel a year, according to the Energy Saving Trust.
Drivers could save an average of £270 each, or 20p for every litre of petrol and diesel, by following a range of smarter driving tips.
Simple things such as avoiding heavy acceleration and braking, slowing down and keeping tyres correctly inflated can contribute to the potential savings, the trust said.
Other ways to save money are going up to a higher gear earlier, turning air conditioning off, turning engines off if stuck for long in traffic and removing unnecessary roof racks.
It is estimated that motorists, on average, drive 8,347 miles annually. They could save 74p a day if they follow the smart-driving advice.
Tim Anderson of the Energy Saving Trust said: "Smarter driving techniques are easy to adopt but can make a huge difference at the pumps, which is more important than ever in these tough economic times.
"If every driver in England adopted the trust's tactics, they could save around £6.6 billion a year."