Having a puncture is always inconvenient. It’s not just the disruption it causes but if the tyre can’t be repaired, you need to source a replacement. What kind of tyre should it be? And is it a problem if you pick a different brand to the ones your car is already mounted with? Read on to find out.
What does mixing tyres mean?
There are multiple ways you might mix tyres. They might be made by different manufacturers. They may be a different construction or they may have different tread patterns. You might even combine winter and summer tyres.
Mixing constructions is illegal
There are two types of tyre construction: crossply and radial ply. In the UK it is illegal to have a combination of the two on the same car. Crossply tyres have the plies that make up the tyre’s structure overlapping on a diagonal. They are very solid but can suffer from heat build-up.
Radial ply tyres have the plies going round the tyre at 90 degrees to the direction of travel. They are more flexible, make the ride more comfortable and they run cooler than crossply tyres. The majority of tyres on cars nowadays are radial.
Why isn’t mixing tyre brands so good?
There’s nothing wrong, in the legal sense of the word, with mixing brands. It’s just you’re unlikely to make the best of your car’s handling properties by doing so.
Car makers go to a great deal of trouble to choose the tyres they fit their cars with. They ask tyre manufacturers to pitch for the right to supply tyres for the cars during the development process. The chosen tyre tyre manufacturer will then spend many hours and millions of pounds developing tyres for those specific cars.
Swap a Continental for a Michelin and you’ll be spoiling all that hard work. The tyres will have different tread patterns and be made from different compounds of rubber. This will mean in extreme conditions the tyres may perform differently with varying levels of grip.
It’s worth remembering that if you bought your car second hand, the tyres it’s fitted with may not be the ones it rolled off the production line with.
What about mixing different tread depths?
It’s fine to mix different tread depths and you frequently can’t help it ‑ unless you’re wealthy enough to replace all your tyres in one go, whenever you only really need to renew one. In an ideal world, you should put the newer tyres on the rear wheels. This is because they will have more grip. It’s considered safer for a driver to cope with a lack of grip at the front than a skid from the rear wheels losing traction.
Mixing winter and summer tyres?
Tyre makers never advise this. It will give differing amounts of grip to the front and rear depending on the weather conditions.
In an ideal world, what should you do?
Ideally, you should replace the tyre with the same size and type that the car maker recommends in the vehicle’s user manual. Again, in a perfect world, you’d swap at least two tyres at the same time. And you’d have the newer tyres mounted on the rear axle while the two worn tyres go on the front. One final thing: at the very least make sure that the new tyre has the correct speed rating and load index for your car. You will find these in the user manual.