Tyre Speed rating query

bazz26

Folks,

I am looking at replacing 2 tyres. Existing tyres have a W rating but the ones I am looking to buy have a Y rating. Both 2 new tyres will be put on the same axel so my question is, is it ok to have tyres with different speed ratings as long as they are the identical on the same axel?

Car is a 06 Volvo S40 diesel btw and these are the tyres I am looking at buying:

http://www.camskill.co.uk/products.php?plid=m4b0s304p6202

Seth Brundle

I don't think that you will be going that fast so you should be fine!
W = max speed of 168mph/270km/h
Y = max speed of 186mph/300km/h


Worth the read: www.carbibles.com/tyre_bible.html

Saab Ed

Y has a higher speed rating than W so it should be ok. You should never go back a speed rating

http://www.tyresave.co.uk/tyrspeed.html

bazz26

Thanks guys, there is no chance the S40 would hit those speeds but just wanted to make sure. There is a good few thousand miles left on the other two tyres yet but will replace them with the same tyres then.

On a similar note I tried my local tyre centres and found that they stocked very little brands in the size I need (R17/205/50). Anything they did stock were either high end or cheap Korean/Chinese brands I never even heard of. I have pretty much settled on the Falkins as I had them on a previous car and found them to be a fine middle of the range tyre.

R.O.R

Saab Ed wrote: »

You should never go back a speed rating

Is there any technical reasoning behind this Ed? We will quite often replace factory spec tyres with H rated conti. I can't see why we should pay the additional costs to put V's on to a Passat 1.9Tdi Highline just because it came that way from factory.

The majority of cars we have probably can't make 210 km/h so I'm not sure why H rated wouldn't be good enough.

bazz26 - the Volvo tyres on the SE 17" Wheels are a pain. Slightly strange size so it's either high end big bucks, or low end widowmakers.

Think I put Pirelli P6000 on the wife's V50, but got a very good deal on them.

Seth Brundle

R.O.R wrote: »

Is there any technical reasoning behind this Ed? We will quite often replace factory spec tyres with H rated conti. I can't see why we should pay the additional costs to put V's on to a Passat 1.9Tdi Highline just because it came that way from factory.

The majority of cars we have probably can't make 210 km/h so I'm not sure why H rated wouldn't be good enough.

bazz26 - the Volvo tyres on the SE 17" Wheels are a pain. Slightly strange size so it's either high end big bucks, or low end widowmakers.

Think I put Pirelli P6000 on the wife's V50, but got a very good deal on them.

If the car did manage to achieve the max speed intended for its original tyres but whilst on lower rated ones then you may expect a bit of a bang. Who then is responsible???

Saab Ed

If memeory serves me ( its been a while since I was in the tyre game ) not only is the speed rating the maximum speed the tyre can be driven at , it also determines other things like rubber compound, side wall strenght and things like that.

R.O.R

kbannon wrote: »

If the car did manage to achieve the max speed intended for its original tyres but whilst on lower rated ones then you may expect a bit of a bang. Who then is responsible???

If it's within Ireland - then I'm going to blame the driver for coc*ing around in excess of 210 km/H. If he's on the Autobahn then he better have our permission to take the car out of the country.

Most of the vehicles which are capable of excess of 210km/h will probably have a wheel combination where H's aren't available (like the Volvo). I've just checked a couple of old favourites and the Passat 2.0TDi 140ps is only good for 209km/h. As a large portion of the fleet would be 1.9Tdi's they are unlikely to break the limit for H's (although, they take next to no time getting up to max speed - TDI POWER!!!)

BlackWizard

I didn't know tyres had speed ratings..

So if say for instance I was doing 200kph on the road.. and my tyres where type U (190kph) , when can I expect some damage to happen? Has it happened already?

My steering wheel shakes quite a bit so I'm getting that fixed this weekend (wheel balancing I reckon). I hope this isn't because I have damaged tyres or something.

Saab Ed

Dont worry too much. Its to do with prolonged speed , heat and increase in pressure. Autoban driving and the like. A quick short burst on any Irish road shoulnt cause to much trouble........mind you dont try it

BlackWizard

Of course. Speed limits are 120mph here anyway!

I guess I can feel safe now and go for a snooze with the foot down on the M1 knowing I'm driving on safe tyres

bazz26

R.O.R wrote: »

bazz26 - the Volvo tyres on the SE 17" Wheels are a pain. Slightly strange size so it's either high end big bucks, or low end widowmakers.

Think I put Pirelli P6000 on the wife's V50, but got a very good deal on them.

Tell me about it. Most places stock 215 or 225/50/R17 but not 205. The more unusual the size tyre the more they cost. Makes it difficult to try and get a good price on them. I'm going with the Falkens however, the online reviews kind of backup my previous experience of them.

Mycroft H

Dont see the point of high speed tyres on our roads as the speed limit is 70mph and most cars will stay under 90mph if the driver decides to floor it.

Seth Brundle

landyman wrote: »

Dont see the point of high speed tyres on our roads as the speed limit is 70mph and most cars will stay under 90mph if the driver decides to floor it.

1. we don't have a speed limit of 70 (or any other number)mph since we went metric some years back!
2. people travel abroad, go on track days, etc. and will need appropriate tyres to match the car! Also most sizes will not be available in all speed ratings. My rear tyres for example (IIRC 255/40/17) are only available in V, W or Y on the camskill site whereas tyres for my old Fiesta are only available in T.

blackbox

AFAIK you are supposed to get tyres to match the maximum speed your car is capable of, not the speed you intend to drive at. This is partly because the car could, as mentioned above, be driven at the higher speed, but also because the car will generate greater acceleration, braking and cornering loads.

On the other hand, higher speed rating tyres may have less tread, and wear more quickly, so putting Y rated tyres on a slow car could be a waste of money.

Head The Wall

It's not just about speed but grip also. Better quality tyres are usually softer but wear faster. There's immense difference in a good and a crap tyre

Blitzkrieger

Worth remembering that the speed rating means the manufacturer guarantees that they will hold up at their top speed for ten minutes only. If you're driving fast for a long period of time, or for short bursts often, you might be better off getting higher rated tyres than your car actually needs. I always get Z rated tyres even though my car's probably only geared for 160mph and I'd rarely be above 100.