ONLY one in ten petrol station prices are fair for unleaded or diesel fuel, researchers found.
And small local forecourts are giving drivers a better deal than the big boys.
Recent falls in oil costs mean the price at the pumps should be at least 10p-a-litre cheaper than the average of 188p.
Around 174p is now seen as fair but RAC analysis at 4,500 forecourts found just 157 were selling petrol for between 170p and 179.9p and 125 of those were independently owned.
Just 250 were selling diesel at a fair price too, 197 of which were independent.
RAC spokesman Simon Williams said: “Weekly wholesale petrol prices have fallen by a massive 17p-a-litre to 135p-a-litre.
“Yet average pump prices have reduced by a paltry 4p.
“It’s time for every retailer to do the right thing and cut their prices to more reasonable levels.”
The AA also found the bulk of forecourts holding back on price drops, with petrol 50p-a-litre, or £27-a-tank, more than a year ago.