Zr Y Rated Meaning

What does y rated and ZR rated mean. I know its speed difference but what does each mean

Originally Posted by bmw540i

What does y rated and ZR rated mean. I know its speed difference but what does each mean

ZR=149mph+

Y=186mph

http://www.tirerack.com/tires/tirete...eral/speed.htm

Any compelling reason to get Y over ZR assuming that your car will never be able to hit 186mph?

Originally Posted by alee

Any compelling reason to get Y over ZR assuming that your car will never be able to hit 186mph?

Well, if I understand correctly then ZR rated tires are always rated W or Y in addition, because ZR just says 149mph and above, but doesn't specify how much above. The manual should say wheather they are ZR W or ZR Y. My pilot sports sidewall markings say ZR, but according to tirerack, they are actually Y rated. Somebody correct me if I didn't get this straight.

Originally Posted by marcelgood

Well, if I understand correctly then ZR rated tires are always rated W or Y in addition, because ZR just says 149mph and above, but doesn't specify how much above. The manual should say wheather they are ZR W or ZR Y. My pilot sports sidewall markings say ZR, but according to tirerack, they are actually Y rated. Somebody correct me if I didn't get this straight.

The actual speed rating is behind the load rating...It'll say something like xxx/xx/ZRxx 91W, which will indicate a Z rated tire (capable of 149+mph) but should not go over 154mph, which is W rated tire's theoretical limit. If it says something like xxx/xx/ZRxx 89Y, it means the tire can handle up to 186mph.

I was once told that the higher the speed rating, the better; it indicates better structural integrity at 'lower' speeds, as well. Anyone care to refute or confirm this?

Originally Posted by The HACK

The actual speed rating is behind the load rating...It'll say something like xxx/xx/ZRxx 91W, which will indicate a Z rated tire (capable of 149+mph) but should not go over 154mph, which is W rated tire's theoretical limit. If it says something like xxx/xx/ZRxx 89Y, it means the tire can handle up to 186mph.

The speeds quoted reflect the tires ability to hold that speed for one hour straight So there's a little safety margin built in for those of use that might hit solid triple digits for a few seconds every once in awhile But don't complain to me if you blow a tire at 150

Originally Posted by StahlGrauM3

The speeds quoted reflect the tires ability to hold that speed for one hour straight So there's a little safety margin built in for those of use that might hit solid triple digits for a few seconds every once in awhile But don't complain to me if you blow a tire at 150

Don't worry about me...I hit sustained triple digit speeds mostly on the track. It's STUKA/Butthead we need to worry about.

There is a valid reason to buy the highest speed rating you can tolerate!

Speed rating is based on the ability of the tire carcass to sustain the centrifical force, and the compound to sustain the high temps found during high speed cruising.

...With this in mind, a tire with a high speed rating of ZR or better will be much more stable, and less likely to blow, in the event of a sudden pressure lost at normal speeds. Those first critical seconds... when the tire pressure drops to zero... and the rim is pressing a flat tire against the pavement at speed... are when the extra heat tolerance and reinforced sidewalls will mean all the difference in the world.

I can't say a TR or SR tire will fail, but I will say a ZR or YR tire will fail in a much more controlled manner.

I will not let my wife (or myself) drive on tires with less than an HR rating. Sure, they cost a bit more, and ride a bit harsher... but the safety margin is everything.

The "official" speed ratings are S, H, V, Z. Those are the ones you find actually in the tires size designation (except they don't put an S in there).

So you get a 205/50HR15, would be an H rated radial (R) tire.

The highest rating is Z, which is above 149. But the tire manufacturers got worried about the speed potential for the super cars and started with additional ratings for Z tires to indicate the actual speed rating above 149. So Y or W rated tire is really a Z rated tire, with additional info.

That is why the Y or W, etc. is indicated folowoing the offical tire size and rating designation.

The higher the tire rating the better the construction to take the higher heat of high speed running. Typically the better handling tires end up with higher ratings.

Originally Posted by Pinecone

That is why the Y or W, etc. is indicated folowoing the offical tire size and rating designation.

Not all have the Y rating. Some Z rated tires actually are Z, 149+ with no upper cap. Well, the theoretical top speed of modern sports cars are around 240mph.

Guess what the Big Mac come shodded with?

There are plenty of cars now capable of breaking the Y rating nowadays, and their tires come with Z rating without the upper cap as indicated by the Y and the W.

Andy
02 M3 CB/Cloth SMG

Originally Posted by Stuka

Not all have the Y rating. Some Z rated tires actually are Z, 149+ with no upper cap. Well, the theoretical top speed of modern sports cars are around 240mph.

Guess what the Big Mac come shodded with?

There are plenty of cars now capable of breaking the Y rating nowadays, and their tires come with Z rating without the upper cap as indicated by the Y and the W.

Andy
02 M3 CB/Cloth SMG

The problem is, if you get a Z rated tire (and ONLY Z) you don't know whether the tire is only good for 150 MPH or 250 MPH. That is why the Y and W rating came about.

Yes, there are some Z rated tires good for 240 MPH, but you can't tell by the rating.