Petrol theft has surged by 62% compared with a year ago, according to new figures compiled for the BBC, with one forecourt owner saying drive-offs are costing him £2,000 a week across his five sites.
The data from fuel theft recovery company Pay My Fuel comes as petrol and diesel retailers say their staff have also faced a jump in abuse because of high fuel prices caused by the US-Israel war with Iran.
Since the conflict began, the cost of filling a typical family car with petrol has risen by £14, while a typical tank of diesel has gone up by about £27.
The government said fuel thieves "must face the full force of the law" while police said forces were taking a proactive approach to the issue.
Josh, a petrol retailer with five garages in the south of England, said he was experiencing about five drive-offs a week now at each garage, whereas it was previously one or two.
