Petrol sales have plummeted in the last five years, according to official figures.
In 2007, forecourts sold 22.87 billion litres of petrol but the annual figure had slid to 17.42 billion litres by 2012, Government statistics highlighted by the AA showed.
Diesel sales, though, have risen slightly over the last five years, going up from 14.80 billion litres in 2007 to 16.73 billion litres in 2012.
Looking at the most recent years, the figures showed that the 2012 petrol total of 17.42 billion litres compared with 18.27 billion litres in 2011. Diesel sales rose from 16.24 billion litres in 2011 to the 2012 figure of 16.73 billion.
Taking petrol and diesel sales together, fuel stations sold 37.67 billion litres of fuel in 2007 but only 34.16 billion litres in 2012.
The AA said that the decrease was equivalent to 35 days of fuel sales being lost since the start of the credit crunch.
AA president Edmund King said: "Greater take-up of diesel cars and smaller petrol vehicles has contributed to this overall decline in UK fuel sales over the long term. However, soaring pump prices have taken a huge toll on petrol sales more recently - during the 10p-a-litre price surges last March and October pump sales of petrol fell by up to 5%."
He went on: "The trouble is that, with global economic recovery, the stock market will predict greater oil and fuel demand and push up commodity values accordingly.
"Drivers' fuel consumption and retail survivability are already precarious. What will happen when the speculators pump themselves up with bullish sentiment and send prices soaring yet again?"
The AA was highlighting figures produced by the Department of Energy and Climate Change.