Mixing Tyres: Different Brands, Two New Tyres, and Why They Go on the Rear
Ask a tyre maker and the answer is simple: four identical tyres, same brand, same pattern, same size, same age. Ask most drivers and the reality is a mix - one tyre replaced after a nail, two replaced last year, the other two from the previous owner. Mixing is not automatically wrong. Some of it is harmless, some of it affects how the car behaves in the wet, and one kind can damage the car. The rules are short, and every major manufacturer publishes the same ones.
On the same axle: match
The two tyres on one axle should be the same size, the same construction, the same pattern and ideally the same brand and the same wear. The car steers and brakes with both of them together, and if one grips or rolls differently from the other, the car pulls under braking and behaves unpredictably in the wet. That is why a single tyre is the one replacement nobody in the trade likes to do, and why our minimum order is two: a pair on the same axle is the smallest change that keeps the car balanced.
If you must replace one - a sidewall cut on a nearly new tyre, say - match it to its partner exactly, and put the pair on the same axle. Never mix a run-flat with a standard tyre on an axle, and preferably not on the car; our run-flat guide explains why they behave so differently when punctured.
Between axles: it can differ, within reason
Different brands or patterns front and rear are common and, on a two-wheel-drive car, acceptable, as long as each axle is matched and both pairs meet the placard's size, load index and speed rating. The car will not feel as consistent as it would on four matching tyres, especially in the wet, because the front and rear grip differently. But it is a normal way to run a car between full sets. What you should not do is put a tyre type the car was never meant to have on one end only - an all-terrain on the rear of a car with highway tyres on the front, for instance, which our all-terrain guide touches on.
The one thing to keep the same across all four is the tyre category. Mixing summer and winter tyres, or very different speed ratings, gives the car two different sets of handling that change with the weather and the speed.
Two new tyres go on the rear
This is the rule that surprises people, and it is the one the makers are most consistent about: when you replace two tyres, the new pair goes on the rear axle, whichever wheels drive the car. Michelin, Bridgestone, Continental and the others publish it, and it comes from wet-handling tests that anyone can watch online.
The reason is what happens in a corner on a wet road when one axle loses grip before the other. If the front tyres have less grip, the car runs wide - understeer - and the natural reaction, easing off and steering a little more, brings it back. If the rear tyres have less grip, the back of the car slides out - oversteer - and the car spins. Most drivers cannot catch that, and it happens faster. Putting the deeper, newer tread on the rear means the rear keeps its grip in the wet for longer than the front, and the car fails in the way that is easier to control. On a front-wheel-drive car this feels backwards, because the front tyres do the pulling and wear faster. The makers' answer is to accept that, rotate regularly so the wear evens out, and keep the best tread at the back when you can only replace two.
If the car's handbook says otherwise for your specific model, the handbook wins. For the great majority of cars it does not.
All-wheel drive: the case where mixing can damage the car
On a car that drives all four wheels permanently or on demand, the tyres are connected through the drivetrain - a centre differential, a viscous coupling or a clutch pack, depending on the system. Those parts are built to allow small, momentary speed differences between the axles, as in a corner. They are not built to absorb a permanent difference, which is what you create when the tyres on one axle are a different size from the other, or are much more worn: a smaller tyre rolls more times per kilometre than a larger one, so the coupling is working continuously, even on a straight road, and it overheats and wears.
For that reason most all-wheel-drive manufacturers require all four tyres to match in size and pattern and to be within a small difference in wear - commonly quoted as a few millimetres of tread, and sometimes as a small difference in rolling circumference; the handbook gives the figure for your car. Replacing one or two tyres on an all-wheel-drive car that has significant wear on the others can mean either replacing all four, or having the new tyres shaved to match the old ones, which some shops offer. Ask before you buy two. It is also why rotation matters most on these cars: it keeps all four wearing at the same rate so they can be replaced together.
Mixing ages and wear
Two new tyres and two half-worn tyres on a two-wheel-drive car is the normal state of affairs and is fine, with the new pair at the rear. Two new tyres and two that are at the wear bars is not a mix, it is a car that needs four tyres. Age matters as well as tread: a pair that is at or past five years from its date code is due regardless of how it looks, and our DOT code guide shows where to read it.
Direction and sides
Two more things that count as mixing even when all four tyres are the same product. Directional tyres have an arrow on the sidewall and must rotate in that direction, so a tyre moved from one side of the car to the other has to be turned on its wheel. Asymmetric tyres have an "outside" marked on the sidewall and must be fitted that way round. Either one fitted backwards works less well in the wet, and a tyre shop should catch it, but it is worth a glance after any fitting. Our guide to wear patterns shows what a wrongly fitted tyre does to the tread over time.
Frequently asked questions
Can I mix tyre brands on my car?
On a two-wheel-drive car, yes, as long as the two tyres on each axle match each other and all four meet the placard's size, load index and speed rating. On an all-wheel-drive car, keep all four the same and within the maker's wear limit, because a mismatch works the drivetrain.
Why do new tyres go on the rear when my car is front-wheel drive?
Because in a wet corner a rear axle with less grip makes the car spin, and a front axle with less grip makes it run wide, which is far easier to control. The deeper tread goes where losing grip is most dangerous. Rotation keeps the wear even so you are not replacing the fronts alone every time.
Can I replace just one tyre?
Only if its partner on the same axle is the same tyre with similar wear; otherwise replace the pair. On an all-wheel-drive car, a single new tyre next to three worn ones is the mismatch most likely to damage the drivetrain, and the usual advice is to replace all four or have the new one shaved to match.
What is the maximum tread difference on an all-wheel-drive car?
It varies by manufacturer and is set in the handbook, often as a few millimetres of tread depth or a small percentage of rolling circumference. If the handbook gives no figure, keep all four within about 2 to 3 mm of each other and matching in size and pattern.
If any of this leaves you unsure about your own tyres, bring the car to your nearest branch and we will look with you - we have 8 across the UAE, the head office is on Al Nahda Street, Industrial Area 8, Sharjah, and we are open daily from 9:00 AM to 10:00 PM. You can also order on gcco.ae and choose mobile fitting at checkout, or message our team on WhatsApp at +971 800 525 - a real person will answer. Toll free 800 525.