Police Scotland has more than 250 cars over a decade old, figures have revealed.
A total of 870 cars, about a quarter of the fleet, have driven 100,000 miles or more, with 126 covering between 150,000 and 200,000 miles.
The average vehicle was four to five years old with up to 50,000 miles on the clock.
The Scottish government insisted the police resource budget was being protected in real terms.
Earlier this week Scottish Police Authority (SPA) papers revealed the £56.2m gap between the police’s proposed capital spending and the funding from the Scottish government this year.
The figures on police vehicles were obtained by the Liberal Democrats under a Freedom of Information request.
The party’s justice spokesman Liam McArthur said: “Staff at every level of the national force have raised concerns about serious budget pressures.
“The fact that they are carrying out their duties in vehicles approaching 200,000 miles on the clock is just another symptom of the pressure that Police Scotland is under.”
At an SPA board meeting on Thursday, the proposed budget was passed, with the £11.2m funding envisaged for the police fleet in 2019/20 in a three-year plan in 2018 being reduced to £2.9m.
The budget proposal said: “Police Scotland will ensure that the fleet continues to meet its 95% availability target, however vehicles will be replaced less frequently with the result that the fleet has to spend more time off the road undergoing (more expensive) repairs and incur higher fuel costs.”
The budget approval follows concerns raised at the Scottish Police Federation (SPF) conference on Wednesday.
Andrea MacDonald,chairwoman of the SPF, which represents rank and file officers, told the conference the fleet was a “disgrace”, with “inadequate” police patrol cars “held together with duct tape”.
She said that two weeks ago in Kirkcaldy, Fife, only two of nine police vehicles were roadworthy, and one had clocked up 140,000 miles.
Chief Constable Iain Livingstone said: “Our maintenance team do an excellent job and we have over 96% of the fleet on the road.