You may know modifying your car can increase your insurance premium, but do you know which modifications have the biggest effect?
Turns out, fitting a turbo is the single-most expensive addition, pushing up the average premium by £494 – an increase of 132 per cent. No surprise here, given a faster car makes a crash statistically more likely.
What is surprising, however, is the second most expensive modification. Purely aesthetic additions such as a bonnet with a bulge or flared wheel arches increased the average premium by 66 per cent.
The third most expensive modification was changing the gearing transmission (presumably to increase acceleration), resulting in an average increase of 63 per cent.
Fourth place, fitting a complete body kit, saw the average increase by 41 per cent, suggesting those who go all-out drive more carefully than those who just change one or two bits.
Meanwhile fifth place, with an average increase of 41 per cent, went to removing the rear seats and adding a roll cage – race and weight-saving measures, basically.
Upgrading the brakes so they are more powerful came in sixth, with an increase of 36 per cent; the same increase you would expect to pay if you changed the paintwork.
Rounding off the list is changing a vehicle’s exhaust system (an increase of 26 per cent), upgrading the suspension (25 per cent) and adding go-faster stripes, decals or badges (22 per cent).
MoneySuperMarket consumer affairs expert Kevin Pratt said: “Insurance is based on risk, and modifying your car is a warning sign to insurers.
“For example, spoilers or turbo engines will mean a vehicle goes faster, and therefore increase the likelihood of an accident, while car phones and sat-navs are attractive to opportunistic thieves, so insurers balance the scales by pushing premiums up.”
It may seem cheaper to avoid declaring modifications, but Pratt went on to explain why it could prove far more costly in the long run: “When you change anything about your car, you change the original specification which may invalidate your policy if you don’t inform your insurer.
“Reporting the changes might mean a higher premium, but having an invalid policy is considered fraudulent and could reduce or even remove the prospect of a pay-out if you had to make a claim.”
The good news is that not all modifications increase how much you pay for car insurance. Parking sensors can reduce what you pay by 13 per cent, for instance, while having a tow bar could save you 20 per cent.
Comparison website MoneySuperMarket used data from 2.3 million quotes for vehicles that mentioned at least one modification to determine each average insurance premium increase.
Such is the rising cost of motoring, new research has revealed more and more drivers are turning to black box insurance policies in a bid to save money.