So when I got the new TPMS valves fitted to my 18" BMW winter wheels which were required for my new 640d I got a new pair of Pirelli run flat Sottozero's so I now have two wheels with brand new tyres and two with circa 6.0mm tread (same Pirelli run flats and obviously all the same size rather than the summer staggered set up). I think best practise is to fit the pair with the newest / deepest tread on the rear regardless of which wheels are driven but thought I would ask what you guys thought? Many Thanks
Definitely rear for me. Both for rear traction and lateral grip. Plus engine/gear braking, which is a good skill to develop for driving in snow. Peter
Thanks for the quick reply Peter. Those were my thoughts too, just wanting to double check before doing the switch next weekend.
I always put the pair of wheels with the most tread on the rear each winter, when swapping from summer wheels. Peter.
l would not fit just two winter tyres to my car. for me it would have to be four winter tyres or none. l would never mix summer and winter tyres brand new winter tyres on the rear will give good traction on a rear wheel drive car but you will have a huge grip imbalance when you try to brake or turn the car with the part worn summer tyres on the front of the car most of the braking force and all of the steering input is through the front tyres so very little grip on the front and loads of grip on the rear could be a recipe for disaster so for me it would be four winter tyres or no winter tyres
It is four winter tyres I was asking about all the same make / size / pattern. Just two are brand new and two have about 6.4mm tread so I was asking whether people thought front or back for fitment. I would never mix summer and winter tyres.
My bad must have still had sleep in my eyes at 6.59am and only half read your post now l have read the original post properly l would agree with the masses and put the new tyres on the rear
And the reason for that is the widely held belief that for the average driver a rear wheel loss of traction/adhesion would result in an oversteer situation which would be more dangerous for them than understeer. So most tread on the rear to avoid oversteer regardless of whether FWD or RWD. I can't remember who it was said something like: "Understeer is going straight on through the hedge - oversteer is going through the hedge backwards."
I had a practical demonstration of this many years ago. New tyres were fitted to the front of my Saab 9-5 Aero on the misguided perception that this would aid grip and handling. Found out that this wasn’t the case as I went backwards around a slightly damp island. Swapped rear to front as soon as I got home, shaken and stirred! Clearly a case of talent not matching the speed/conditions, but a lesson learnt.
Unfortunately over the years I have seen quite a few of these type of outfits(especially the big chains) just replace the ones that are worn, if this happens to be the fronts they can't be bothered to swap the wheels front to back.... no profit in doing unnecessary work that doesn't earn extra money and most people have no idea. Good tyre fitters will make sure they are on the rear....
Not always so easy to get the timing right with staggered setups. If you require front tyres when the rears are part way through their life. Although staggered do help a little, with their ability to help reduce oversteer, as long as there is enough tread for lateral grip. Peter
When we collected our car last month, the BMW dealer explained they had replaced the front tyres (with Falkens) due to being at 3mm, the original Goodyear rears still at 6mm (as it is fwd). They didn't bother to swap them round either. Also got a non-matched set now.