Hello NR, the section about "winter tyres" is a bit frayed. Winter tyres do not automatically come with a larger tread block pattern. What they do have is a tread pattern designed for cutting through the water on the tarmac surface and as a process of this, also the efficient removal of the water. In fact this is also not a true definition of a "Winter Tyre" either. While rain is more prevalent during Winter, we also get heavy downpours in Summer and so Summer tyres also need the ability to perform in wet conditions.
The true aspect of a Winter tyre is the compound it is manufactured from. A winter tyre has more rubber in its make up than a summer tyre. A summer tyre contains more silicone in it which is harder than rubber and so also gives a longer wear life on a like for like test.
The silicone in a summer tyre stays soft due to the higher average climatic temperature. In Winter, below about 7degrees centigrade, the silicone hardens up and can not perform well. This is where the Winter tyre comes in, with its greater percentage of rubber, which stays soft all through the winter and freezing temperatures. The ability to fit studs is an extra for extreme driving conditions. As it is, most modern winter tyres have "sipes" as part of the tread block pattern. These are many parallel thin cuts across the tread blocks, often in a zigzag pattern. These "sipes" increases the ability of the tread blocks to move and grip under various cold weather situations and are pretty effective in slippy freezing road conditions. While there is no good grip on black ice without studs, the sipes do help to some degree.
Ice and snow are very different when it comes to tyres. Ice needs studs and sipes help a bit. Snow needs a large tread block pattern like off road or mud tires. All terrain tyres have some useful ability in snow but care must be taken as they can still have traction problems.
Any reduction in tread depth below about half of the original tyre tread depth makes a significant difference in snow traction.
Winter tyres can easily be used all year round on a vehicle. While they may wear out faster than a summer tyre, the wear rate is not ridiculous. It would depend on the type of driving, the distance and the vehicle as to whether it warrants having a summer set and a separate winter set. The advances in tyre design have moved on since the 70's & 80's and even the 90's and so a lot of info that was relevant back then, is obsolete now.
Most drivers & garages have been fitting "Summer "rated tyres for many decades as the norm, without necessarily an understanding of the important physical characteristics of vehicle handling and safety this entails to the end user. This last few years the tyre companies have managed to change the garage industries perceptions and thinking on this. While it has not spread all throughout the trade, it is gathering apace and the consumer is also now becoming more aware of this important aspect of their own vehicles handling and braking performance.
A winter tyre should have a snowflake or a symbol of a few mountains as a raised logo on the sidewall.
Regards, TL
Snow chains or socks are for compressed snow, like on A roads for HGVs and other vehicles. Studs are for ice.
I believe chains also work on ice but not as effectively as packed snow.
(26 May 2013, 06:57)Steve Wrote: I have BFG Mud tyres on my 4x4, they are exceptionally hard wearing and absolutely fine for use on the road, even in the wet, which surprised me as the remoulded mud tyres I had on a previous car were like driving on ice when on wet tarmac. I will buy them again if I ever manage to wear them out.
Hi Steve. You will have trouble wearing out the BFG's. Most of the ones I have seen have never worn out. They just get harder and harder with age and eventually crack up. This makes the ride more uncomfortable and then they do not handle at all well in the wet or cold when they have a few years on them. That is my own experience with BFG's and I have no doubt there will be alternative views :-) Regards, TL
Any mud tyre, remould or not is very slippy to drive on wet tarmac. This brought it home to me how important tyre choice is and then the sense to drive the vehicle appropriately to the road conditions. It was after this that I started researching a bit about tyres and found out how interesting it all was.. to me anyway.. lol.