Hey, I'm wondering if anyone has blown a tire due to exceeding the speed rating. A friend of mind told me he was going 140 in an SHO Taurus, and he knew the speed rating was less then a V.

What are the details of exceeding the speed rating?

 

Before everyone comes on here and starts talking about how they went 130MPH in their old beater caprice and nothing fell apart....
It's just for warantee or liability. You can usually go pretty fast in a low speed rated tire - just not for a very long time, or if the tire is super old.

If you blow a Z rated tire going 100MPH, you can probably sue, and or get a bunch of free tires. If you blow the low speed rated tire (say, H?), at like 150MPH, you don't have much recourse as far as law/warantee goes...

 

Speed ratings are based on a sustained speed over a period of time. If you're running 100 mph for about an hour, the tire will heat up a lot. A higher speed rating tire will prevent the tire from heating up and causing a failure. The speed rating is also based on the load of the tire.

Of course there's always those people who have speed rated tires which are designed not to heat up and they're in the water box trying to smoke the tires to heat them up. It just doesn't work.

There are many fast cars on the dragstrip that do not have speed rated tires. They're just not at those speeds long enough to affect the tires.

For those short bursts of speed, a standard H rated tire will survive just fine but if you're running in the Silver State Challange, part of the rules is that you have speed rated tires at or above the speeds you'll be running.

Having speed rated tires also means running them at the proper air pressure. The tire is trying to disipate heat and if it's underinflated or overloaded, it produces more heat than normal and the speed rating decreases.

 

Dont know if it was related, but yes I've blown a tire sustaining a speed above its rating and it was a nasty blowout.