Tire Speed Ratings

[Glennman]

I decided to start a new thread since it is a more detailed topic on tires than my other thread.

Tire speed ratings. I didn't know there was such a thing until recently. I usually hold my speed to 70 mph, but I've certainly gone over that from time to time. My tag tires are rated for 68 mph. With my new Firestone FS860 tires being on the way, I believe they are rated for 75 mph, but it appears that the FS860 tires come with either 68 mph (K) or 75 mph (L). This doesn't make sense to me that the same model comes with 2 different ratings.

Is the speed rating an actual limit on the tire, or is it more of a rating that determines longevity or traction? Someone told me that I don't need to worry about it because I am so far underweight that it shouldn't matter. What speed rating do you guys usually go with?

[lhwood]

I'm no tire expert, but here's interesting reading on the subject from Heavy Duty Trucking, a magazine in many truck stops around the country.

https://www.truckinginfo.com/159434/too-fast-for-your-tires

Interestingly, according to this article speed ratings aren't even necessary in the US.

Regards,

[Glennman]

That was a very interesting article. I think I will be ok as long as my tires are rated for at least 75 mph. If the tires I ordered do not have that rating, I'll have to get a different set. I ordered them from a local tire dealer and I put $1000 down. I'll be willing to pay a restocking fee if I have to, but I definitely want the "L" speed rating. Thanks!