Tyre speed rating - starcott
Can anyone explain why there are so many tyre 'speed ratings' available?
Who needs a 'V' which covers up to 149 mph or even an 'H' for speeds up to 130 mph?
As I have no intention of ever going near to 99 mph, should I be looking for a speed rating of 'Q' for 'up to 99 mph'?
Is it satisfactory to mix ratings on the same axle?
Any advice would be much appreciated.
John
Tyre speed rating - robcars
Its not what speed you will do thats the limit but its what the car is specified for thats important. The speed rating also takes into account cornering ability, braking performance etc.

What I dont understand is why all the lower speed ratings are so widely available. If tyre companies concentrated on lesser variations, then it would be simpler for all?
Tyre speed rating - GregSwain
As far as I'm aware, "T" is the lowest speed rating that's readily available on car tyres, with a max speed of 118mph. Bearing in mind we have a 70mph speed limit in this country, there's not really any reason to buy tyres with a higher rating that this....

However, most modern cars have fairly low-profile tyres, which are often only available in "V" and "W" ratings. If you don't drive like a nutter, just buy the cheapest speed rating available. I also can't see any reason why you shouldn't mix speed ratings either (although some tyre-anorak will no doubt correct me!). Provided both tyres are radial-ply (as 99.9% are now) the car should still go where you point it. Different branded tyres will have slightly different characteristics anyway, so IMHO driving with a "H" and a "V" on the same axle would be no different to driving with a Dunlop and a Pirelli.

I'd be VERY surprised if you could find a new Q-rated tyre these days. I tend to buy the cheapest available new tyres (not remoulds) for my car (last purchase was £23 per tyre, fitted), which are invariably T-rated, and sit on 80mph quite happily.
Tyre speed rating - LeePower
Just remember that you will invalidate your insurance by fitting a LOWER speed rating tyre then recommended by the manufacturer.

For example: If it came with H rated tyres originally then you have to fit H rated or better when the tyres want replacing.

Also mixing different speed ratings of tyres on the same axle will fail the MOT test.
Tyre speed rating - mgbv8
I understand that the speed rating is a 10min test (sustained speed at fixed temp) although most tyre manufactures will over design. A lower rated tyre may or may not exceed a higher speed rating but will be aimed at a speciic market. however it is in the area of the cap plies that allows a H rating and reduces tyre failure. The cap ply restricts the growth of the tyre in the circumferential direction.

Although handling issues from mixing tyres may not show up around town, with the MGF the change by Goodyesr from Eagle F1 GSD2 to D3 caused problems and handling issues especially when mixing D2 and D3.
Tyre specification is not only just about speed as high performance tyres with a higher speed rating than required for MGF(V) are also better suited to a mid-engined roadster. These cars require a far stiffer side wall (than front engined cars) to promote predictable and reliable handling characteristics. Toyota recognised this and with Yokohama, developed the Advan tyre range specifically for the MR2, with specially reinforced sidewalls.

It is far better not to degrade tyre choice, not to mix tyres, even out tyre wear ,and replace all at same time at a 3mm depth.

Tyre speed rating - kithmo
Also mixing different speed ratings of tyres on the same axle will fail the MOT test.


Not according to the MOT testers manual.
Tyre speed rating - Bill Payer
Just remember that you will invalidate your insurance by fitting a
LOWER speed rating tyre then recommended by the manufacturer.

No it doesn't. There was a story in the press about this (that an insurance company had failed to pay out) but the company (and others asked) said it isn't true.

I had a company Mondeo a few yrs ago that came with V rated tyres from new but Ford issued a memo to say that H would be OK.
Tyre speed rating - Manatee
RTFM.

It's very common in my experience for tyres of a higher rating to be fitted by the manufacturer than is specified in the manual, e.g. manual says T, car fitted with V.
Tyre speed rating - Hamsafar
The speed rating isn't the speed at which you shouldn't drive, it's the maximum speed at which the tyre didn't fail during load/speed/temperature testing. The car manufacturer will specify a tyre with the optimum characteristics for the car and in almost all cases the tyre speed rating will happen to be much higher than the maximum speed capable by the vehicle due to the nature of the ratings.
Tyre speed rating - Manatee
Ashok, as you have replied to my post, rather than the OP's, perhaps you have misunderstood my point - in the example I gave, it would be fine to use T rated tyres provided any other aspects of specification in the manual are also met.

I agree that the OP should not buy tyres based on what speed he is going to drive at, but if he follows the requirements in the manual he will be fine, even if the car happened to have been fitted with a higher speed-rated tyre from new.
Tyre speed rating - Hamsafar
No, it's OK< I agree with you.
Tyre speed rating - Collos25
I hope you never go to mainland Europe ,at the present time it is an offence in all eu member states to drive a vehicle if it has not got tyres to the standard stated in the log book or in the vehicle specifications.You might get awy with it in the UK but you will not in Germany ,France or Holland .
Tyre speed rating - MW
I am happy with H rating as it is about 40 mph faster than I ever go, but I need new tyres soon. If they are V then even more security, and the price is often the same.
However, is there any other penalty, e.g. wear rates, grip, or for me crucially ride and comfort over H tyres?
Tyre speed rating - Hamsafar
As said before, the speed rating is nothing to do with how fast you go, it is the speed at which the tyre failed on a test bed at it's load rating. Don't get a lower speed rating because you never go that fast, it's not what the speed rating means. I think it's time they scrapped the speed/load ratings, as nobody seems to understand what they mean, On so many forums you read I never go that fast/carry such a load.
Tyre speed rating - GregSwain
The price difference between different speed ratings is sometimes negligable, and to be honest, if you drive, for instance, a bog-standard ford focus 1.6, with a top speed of 115mph, does it really matter whether you put "H" or "V" rated tyres on?

Of course it doesn't. And, it doesn't matter how many of each speed rating you have on the car. As long as each tyre carries the E marking, rotates in the correct direction, and has over 1.6mm of tread, it's legal.

As for "more security", any tyre which is not properly inflated or has damaged sidewalls will eventually fail. Sitting on the legal motorway limit, it wouldn't matter whether you had a T, H, V etc etc. If the tyre is inflated correctly, not damaged and the vehicle is not overloaded, it is very unlikely that a modern tyre will fail.

As for other characteristics of a tyre, e.g. wear, grip etc etc, this varies depending on the manufacturer's choice of compound. I always go for the cheapest tyres personally, but you may have a favourite brand-name.

Anyway, the speed rating is based on the absolute limits of a tyre. You're unlikely to be driving a normal road car at 130mph for 10 minutes, so go for the cheapest of the two tyres. OK, I know it's only a piece of rubber between you and oblivion, but provided it's in good condition, any new tyre out there will work fine on a bog-standard boring family car.
Tyre speed rating - Adam {P}
Wouldn't that invalidate the insurance though?

If Ford say "This car needs (?) speed rated tyres" then that's what should go on.
Tyre speed rating - GregSwain
Only invalidates the insurance if you put on a slower tyre than the manufacturer allows.

In real life, that's unlikely to happen on a normal car though. For instance a Vauxhall Vectra with 195/65R15 tyres will be required to have a minimum of a H rating. Try finding a T rating in that size - they're few and far between. Certainly if you went to a fast-fit garage and asked for the cheapest 195/65R15, it would be an H.

However, if you're so inclined, you could choose to pay extra and have a V-rated tyre fitted, quite legally, but at extra cost. All i'm saying is, given this decision, I'd always opt for the slower of the two suitable tyres because there would be no benefit in fitting a V rated tyre to a family car which only needs an H-rated tyre. Far more important to me is the condition of the tyre.
Tyre speed rating - Hamsafar
Yeah, like why buy a stereo that goes up to 11 when you can get one that goes up to 8 for £25 and I never go up to 11 amyway.
Tyre speed rating - GregSwain
Sarcasm aside, I think there's a slight difference between stereos and tyres - but I couldn't care less about the specifications of either, as long as they do the job.
Tyre speed rating - daveyjp
I've just had my tyres changed and when I first asked for prices I stated the tyres were 205/55/16 91V rating. When I went to check they were actually W rating. The V rated tyres were slightly cheaper, but the tyre fitter said he would refuse to fit V rated tyres on a car which was fitted with W ratings, it would also mean I would have had 2 V ratings and 2 W ratings fitted. His comment was going down ratings is a definate no no.
Tyre speed rating - GregSwain
A definite "no no" when it means the tyre fitter getting less money out of you!

If there were already V-rated tyres on your car there was no reason whatsoever to refuse to fit another pair!! I would've gone somewhere else where they actually checked what your car manufacturer had specified and fitted it - most likely a V-rated tyre.

Proof that speed ratings are a stupid system, when even the tyre fitters themselves don't know what tyres to fit to cars, and end up charging you more for faster tyres you don't need, just to cover their own backside!
Tyre speed rating - daveyjp
A definite "no no" when it means the tyre fitter getting
less money out of you!
If there were already V-rated tyres on your car there was
no reason whatsoever to refuse to fit another pair!! I would've
gone somewhere else where they actually checked what your car manufacturer
had specified and fitted it - most likely a V-rated tyre.
Proof that speed ratings are a stupid system, when even the
tyre fitters themselves don't know what tyres to fit to cars,
and end up charging you more for faster tyres you don't
need, just to cover their own backside!


Read my post again. It was me who thought they were V rated when I telephoned for a quote, when I checked they are actually W rated (first set, factory fitted) - I was wrong. If the manufacturer specifies W rated why compromise safety for a few quid?
Tyre speed rating - quizman
Sarcasm aside, I think there's a slight difference between stereos and
tyres - but I couldn't care less about the specifications of
either, as long as they do the job.



If I am reincarnated as a car, I hope that GregSwain does not buy me.

I just know that he would give me cheapo nasty name tyres, cheap low spec oil, and supermarket fuel! I would much rather have Michelins, Castrol and Shell.




By the way, no offence Greg!!!
Tyre speed rating - DeChristi

I've been asking the same question as I need to replace all 4 tyres and the H and V options are the same price. This article has some useful info:

www.consumerreports.org/cro/news/2009/10/h-rated-t...m

They state: "Tires with higher speed ratings generally have better steering response and cornering grip than lower-speed rated tires, in addition to being capable of higher speeds."

but you also get "a harsher ride and shorter tread life, plus a greater upfront cost."

Up to you which ones you go for based on your budget, your driving preferences, your car's maximum speed and manufacturer's recommendation.

Tyre speed rating - bathtub tom

I've been asking the same question as I need to replace all 4 tyres and the H and V options are the same price. This article has some useful info:

www.consumerreports.org/cro/news/2009/10/h-rated-t...m

They state: "Tires with higher speed ratings generally have better steering response and cornering grip than lower-speed rated tires, in addition to being capable of higher speeds."

but you also get "a harsher ride and shorter tread life, plus a greater upfront cost."

Up to you which ones you go for based on your budget, your driving preferences, your car's maximum speed and manufacturer's recommendation.

In the event of an accident, the authorities and your insurance may have something to say if you've fitted lower speed rating tyres than the manufacturer recommends.

Tyre speed rating - Brit_in_Germany
I was wondering if there would be another aspect to this. If tyres are fitted which are not suitable for the maximum speed of the vehicle, would there be liability for damages if some tea leaf crashes your car while speeding due to a tyre blow out? The same if you sell the car and forget to inform the purchaser in writing perhaps?

Not an issue for me in the land of the non-restricted Autobahn - tyres have to be fitted according to the car's specifications.

BIG
Tyre speed rating - Statistical outlier
I look at it in a slightly different way. My car will do 126 mph I think, W rated is something ridiculous like 160+ mph. I'll never get close.

What happens if I'm doing 80 (say) on a hot day having been braking a fair bit so everything is nice and hot. What now if I have to do a full emergency stop and hard manouvering to avoind something happening in front of me? I want to be sure that the tyres have a chance of being up to it. Normal cruising conditions have nothing to do with it.

I think of it like climbing equipment. My harness is rated to 26 kN, or about 2.6 tonnes. Completely over the top, I only weigh 73 kilos. Do I try and find a cheaper harness that's more suitable? No. If I take a big fall, I want to know the harness will hold it. Tyres are the same.

Anyway, what's the difference in price? On big tyres (225/45R17s on mine) probably £100 for the pair. Over 20k miles, that's half a pence a mile. I could save more than that by just driving slightly more gently, my safety is worth more than that!
 

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