tyre speed rating

larch gurgled happily, sounding much like they were saying:

Umm, Z rated or W rated?

I wouldn't trust a tyre place over the manufacturer. What's the handbook say? Is there an information sticker, mebbe in a door jamb, giving the ratings?

In the UK, there's no legal reason, but your insurer might get a bit antsy if non-standard tyres are ever suspected of being a contributory factor to a collision.

Bear in mind, though, that it's not just the straight line speed - higher rated tyres will behave differently in hard cornering or braking, too.

No - but they might give a slightly harsher ride.

The manufacturer of the car spends an awful lot of money on the research into the right tyre for a vehicle to be approved with. So stick with whatever the maker of the vehicle says and you cannot go wrong. The speed rating is not only about absolute speed, it encompasses maximum accelleration, braking, cornering, load ratings and a whole lot more.

You mean the ZR16 bit? - 205/55/ZR16 91W is what it says on the tyres - I've just gone and checked. I presume that means they are W rated.

Nothing I've found sofar.

I see.

Right, thankyou.

I know it is fine with the W rated tyres. I suspect it will be OK with the V rated tyres, but mytyres might be making an error and so I'm seeking a definitive answer but it seems difficult to find.

See the top speed of your car ... according to the manufacturer. If you car is capable of doing e.g. 150MPH then you must buy tyres that meet the spec of 150MPH or better. I don't know of any case but an insurance company may try to use that as a means of getting out of paying ... if anything - I hope not - happens. As others said, the tyre is not designed just for the top speed but for everything else associated with that speed.

If it helps a little.

Regards Charles

If it is anywhere, it will be inside the fule filler flap on a VW.

Of course V will be fine. Unless of course you're going to abroad, where the speed limits are higher, that's where the specs are for.

Steve

and would the insurance company agree? Does anyone know what info the insurance companies use if they check up on tyres?

Not there - just the tyre pressures and a diesel sticker. On the tyre pressure sticker it says

but that is all - well apart from two pics of some funny little men holding hands!

Tyre speed ratings are established by enginers, not insurers. The speed limit in UK is 70mph. If you are obeying it, and the tyres you are using are rated for at least 70mph[1], it's f*ck all to do with the insurers.

Steve

That's just the part number of the sticker.

John

"Mrcheerful" wrote

Hmm. That will be why it is possible to get the same model with 2 or 3 different wheel/tyre combinations... probably with different speed and load ratings too. It means cost and cosmetics represent a large part in the choice.

What property of a tyre capable of higher speed inevitably makes it do these things better (since you list them, we must presume there's something better about them) than a lower speed tyre - when used on a car that cannot exceed the rating of the lower speed tyre?

Ignoring these and just concentrating on straight line, do you actually know what problem occurs when the rated speed is exceeded?

"shazzbat" wrote

Ah, but your car might be driven by somebody that does not realise the speed limit is lower than the car's top speed.

Reluctantly but sensibly, tyres should be rated for what the car might do. The reality is that the factory price of a tyre is probably unrelated to the speed rating so, unlike the retail customer, the manufacturer might as well fit the highest rating for the size.

The question is, if the tyre manufacturer makes a tyre in, say, V and H ratings for the retail market, is there really any difference other than the lettering on the sidewall?

I do have experience of low rating tyres falling apart when used with excessive amounts of power, it is very frightening, and instantly makes you grow up about using good quality, correctly rated tyres. Tyres are the ONLY contact you have with the road, if they are good quality and the correct spec then they are very unlikely to go wrong. The cost of just one minor accident will be more than the cost of a set of good quality tyres, and if the accident is major or involves human injury then the cost is immense, and I don't mean pounds.

Indeed this could be just a scam to enable them to sell some (the V rated) at a higher price. Similar to Intel and the SX DX scam, or even with current processors where they are rated at different speeds, this is usually artificially reduced to enable slow, medium, fast, bonkers speed/marketing hype to ramp up prices.

and if it (processor marking) is true then how many lives are lost? compared to the potential death market of substandard tyres?

Well done to you. So what is the answer to the question?

We're not discussing sub-standard tyres.

Using a tyre with more power than it is designed for makes it fall apart, I believe it overheats first and then disintegrates, but I do not have a multi million pound research program to show you, just personal experience, which of couse is anecdotal. Ask someone like Michelin, they can give you chapter and verse. If you know better then publish your research, or if you suspect they are lying then publish that too.