“The majority of vehicles are trying to hit 56mph, which is the optimum speed for fuel economy. We’re getting a great deal more breakdowns because cars are simply running out of fuel, sometimes in very dangerous situations. 

“We love to go on about safety issues and being greener, but it’s really only when we are hit in the pocket that people begin to feel personally involved. The cost of motoring has now taken over from the weather as the main topic of conversation during call-outs.”

Friends of the Earth’s transport campaigner Richard Dyer welcomed the RAC patrols’ findings. 

He said: “Avoiding unnecessary car use, using buses and trains and choosing more fuel-efficient cars will save money and cut transport’s contribution to climate change. The Government must help motorists by investing extra oil tax revenues in public transport and cycling facilities, encouraging greener motoring and pushing for tough EU laws on the fuel-efficiency of all new cars.”

The RAC patrols also reported people are combining journeys and only driving when it is essential. 

Companies are asking their drivers to reduce speed.

The RAC said feedback from customers included cars being too expensive to run now, parents walking their  children to school and caravanners not travelling as far to holiday destinations.

Petrol prices yesterday hit 118.48p per litre for unleaded and 131.84p for diesel. 

* The Daily Express is crusading to cut fuel duty and readers can show their support by signing the petition at www.express.co.uk/fueltax