The TaxPayers’ Alliance pressure group described the figures, released after a freedom of information investigation by the Press Association, as “staggering”.
Throughout the UK, police officers put the wrong fuel in nearly 300 times – costing £50,000 in repairs.
Of the UK’s 45 police forces, 40 responded and 33 admitted paying for repairs to a police vehicle after a misfuelling last year – at an average cost of £178 a time.
Some 299 incidents of misfuelling were recorded, costing a total of £53,337. West Midlands Police recorded the most incidents – 66, at a cost of £3,737. The Metropolitan Police had 49 incidents, costing £17,589 to repair.
John O’Connell, chief executive of the TaxPayers’ Alliance, said: “It’s staggering that such a simple mistake is being made almost daily.
“This careless attitude shows a lack of respect for those same taxpayers who both pay their wages and are forced to pay for the repairs. Millions of people manage this task with their own cars by taking a modicum of care – police officers should extend the same courtesy to their vehicles.”
West Midlands Police fleet manager Gary Mallett said mistakes increased after 2013 when the force moved away from internal fuel sites to external fuel stations in a cost-cutting exercise.
He said: “We saw a major spike in the number of misfuels in 2013-14 and addressed this by notifying users and local vehicle leads of the volume and cost of the mistake.
“We also labelled all vehicles with the fuel type as a reminder of the correct fuel that should be used. This has had a positive effect, with around a 53 per cent reduction in the number of misfuels, but more importantly around a 90 per cent reduction in actual cost of repairs.
“We put out regular reminders to staff and this is continuing to have an impact on reducing the problem.”
A spokesman for the Met said that since 2008 its vehicles had been refuelled 1.5 million times and mistakes were “a tiny proportion of total refuelling”.
He added: “The [Met] operates a mixed fleet of both petrol and diesel vehicles with a gradual move towards more petrol, hybrid and electric vehicles. Overall, the misfuelling rate is decreasing.”