A top mechanic has told motorists why they shouldn’t be buying certain types of used petrol and diesel cars. 

American auto expert Scotty Kilmer said road users should avoid “salvaged” or written-off models as these could be slapped with higher fees later down the line. 

Cars which have been written off may be cheap upfront and could be turned into passion projects with a view to returning a vehicle to its former glory.

Those on low budgets could also secure great deals as these models are likely to be the least in-demand cars on the market.

However, Scotty warned that car insurance companies will often “raise the rates” going forward meaning any upfront savings could be handed back in premiums alone. 

Speaking on his YouTube channel, Scotty said: “Today I'm going to tell you why not to buy a car with a salvaged title. 

“It doesn't matter if the title says salvaged or rebuilt. It just means the car was totalled by an insurance company. 

“They only total them for rather large reasons. Let’s say it was flooded. It may run fine now but the water damage may ruin it months down the line.

“Now we are all tempted by low prices but realise insurance companies will often raise the rates if you have one that has been totalled. There are plenty of used cars out there. But stay away from ones that have been totalled.”

According to Compare the Market, insurance firms will usually put damaged cars into a category ranging from models that have to be scrapped to vehicles which are just too expensive to repair.

However, Category N (non structurally damaged repairable) and Category S (structurally damaged repairable) can be purchased. But, they also raised fears around the cost of car insurance with motorists likely to struggle to find affordable cover.

They explained: “You can also buy and sell second-hand S and N write-offs. But these cars may be more difficult and expensive to insure in the future. Some providers won’t insure them at all.

“If you’re considering buying an S or N write-off, first check out how much you’re likely to pay to insure it.”