The IAM is urging drivers to adopt fuel saving techniques or pay the price at the pumps, as the £6 gallon arrives.

Drivers are already using their cars less, with government figures showing a 3.4 per cent fall in petrol sales in the third quarter of 2010 compared to the same period in 2009. But there are also significant economies to be made simply by changing driving style.

IAM chief executive Simon Best, writing in the IAM members' magazine Advanced Driving, said: "Green driving techniques will improve fuel efficiency by up to ten per cent. In other words, if the monthly price of filling up is typically two tanks at £70 each, an advanced driver can save £14 a month, or £168 a year. Advanced driving courses can also lead to significant insurance discounts; an important factor with insurance premiums set to rise by 35 per cent this year."

"Spain reduced its speed limit recently to save fuel but we don't think such radical measures are necessary. The best fuel-saver is a light right foot and anticipation of the road ahead - not a lower speed limit."