Should all my tyres be the same?
Hi, I recently bought a second hand car and noticed one of my rear tyres is a slightly different size (245/45 R18) to the three other tyres (245/40 R18). I am due an NCT in March; can you tell me if this would contribute to a fail? Are there any other downsides to this? Car rides and handles perfectly.
Thanks, Andy K (Kildare)
Andy K (Kildare)Mar 2015 Filed under: tyres
Expert answer
Hi Andy,
It's only a small difference but it could well be a reason for failure. The NCT says that having tyres of differing size or specification is a fail point.
It would be worth your while getting that odd tyre swapped out for one the same as the others. Even with that small difference in the sidewall, the way the tyre reacts and the way heat builds up in the tread is different so while the car might fee fine, its reactions in an emergency situation could be suspect.
I know it's an annoying expense, but honestly, tyres are pretty much the most important thing on the car. Better to make sure they're right.
Neil Briscoe - Complete Car Adviser@neilmbriscoe