Selecting the right tyres for your car can greatly influence your safety and driving experience. There are lots of factors which should be taken into account before you buy. Let's analyse them.
When Should I Replace My Tyres?
In most countries in Europe, it is required by law to replace tyres with a tread depth of less than 1.6mm. Tyre manufacturers have started imprinting tread wear indicators which become visible when the tread gets worn out. This helps drivers see when the tyres should be replaced.
Despite the law minimum, there are tests which show that you should change the tyre when its tread depth drops below 3mm, because of a drastic performance drop. This drop in performance is even more apparent in wet and snow, in which case it could be considered unsafe.
How Many Tyres Should I Replace?
If the tread is slightly worn out, but the tyre has been damaged beyond repair, it should be replaced by a new one. You should purchase the same tyre of the same manufacturer, with the same size, speed and load index. It's safest to mount exactly the same tyre, because otherwise, you could experience all sorts of strange behaviour.
If the treads on both tyres damaged or worn out, it is recommended to replace them with similar tyres. It is recommended that they be of the same type, size, speed and load index, but they needn't be of the same manufacturer.
All Four Tyres
If your lucky, all four tyres on your car will be equally worn out. In that case, you should replace them all together.
Which Size Should I Buy?
Tyres have their dimensions marked on the sidewall. Read page: Tyre size designation for more details and calculate the tyre dimensions (diameter, circumference, revolutuons per mile) from the tyre size designation.
Since the primary function of tyres is carrying weight, you should buy the tyre with the same load index as the original one. The maximum allowed speed the tyre can handle is designated by the speed index, which should also be matched with the original equipment tyre.
If you drive a second hand car, you should check to see whether the previous owner had installed tyres with different dimensions from the original. You can find the original tyre dimension in the manual that came with the car.
Summer, Winter, or All Season Tyre?
If you live in a region with all seasons, by far the best option is having 2 sets of tyres: 4 summer tyres and 4 winter tyres. Unfortunately, some people cannot afford that. However, it is important to understand that summer tyres are a bad fit for winter conditions, and vice versa.
If you live in a region with mild winters, you can get by with summer tyres only. Beware however, that you should install winter tyres when the temperature drops below +7°C(+44.6°F), regardless of presence or absence of snow, because summer tyres will loose their features when that happens.
If you drive a couple thousands of miles a year, mostly in the city, and never over 100mph (160 km/h), standard tyres in mid price range will suffice. Otherwise, you should buy a premium brand tyres, which should reach better mileage.
Tyre Performance Classification
There are three performance classes:
- Standard - with load index S,T,(H) and 13"-15" radius
- High performance – HP - with load index H,V,(W) and 15"-17" radius
- Ultra high performance – UHP - with load index W, Z i ZR and 16"-20" (and bigger) radius
Tyre Quality Classification
Performance and quality should not be mixed. There are three levels of quality within each performance class.
- High-quality. Premium brands: Michelin, Bridgestone, Goodyear, Pirelli, Continental and Dunlop.
- Mid-quality is the broadest group. Each premium manufacturer owns a mid-quality brand: Michelin – BF Goodrich, Bridgestone – Firestone, Good Year – Fulda etc.
- Lower-quality. Some premium manufacturers own low quality brands: Good Year – Debica, Bridgestone – Dayton etc.
Results of the tests conducted by car magazines can be a tie breaker when choosing tyres. If several magazines of this type agree on a tyre's verdict, you may be sure you won't regret buying the tyre.
Ask the Tyre Fitter
You've seen how many factors influence tyre choice, but it is easier if you have a tyre fitter that you trust to help you make the choice.