Temperature ratings

[Falcon_LS]

I've currently got Pirelli Scorpion STR's (265/70-16, 520 AA 112H) on my truck. Had them mounted in June 2008, and did rotations every 6,250 miles (cross rotation one round, traditional back to front the next). I've currently got 66,000 miles on them, and plan a replacement in June this year. The manual recommends a 112 load rating and H speed rating, so that's what I'm looking at. But as far as UTQGS ratings go, I always go for tires with A traction and temperature ratings.

Having said that, how much of a difference is there as far as a tire's resistance to heat is concerned between grades A and B?

Would a B be adequate for long distance driving in high temperature conditions?

 

[Hokiefyd]

If you're looking at H-rated tires, they almost always have an "A" temperature anyways, so you probably don't have to worry about it. Some T-rated tires are showing up with "A" grades for temperature now. They used to exclusively be "B" graded.

Read all about the UTQG ratings here:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=48

 

[The_Jeff]

Remember the UTQG is a US spec and Kuwait is warmer. Sounds like the Scorpions worked well for you.

While a grade B might not itself be worse there could be other design compromises you couldn't otherwise decipher. Do you run 100+ MPH regularly?

 

[Falcon_LS]

Originally Posted By: Jason Adcock
If you're looking at H-rated tires, they almost always have an "A" temperature anyways, so you probably don't have to worry about it. Some T-rated tires are showing up with "A" grades for temperature now. They used to exclusively be "B" graded.

Read all about the UTQG ratings here:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=48


Thanks for the input!

Originally Posted By: eljefino
Remember the UTQG is a US spec and Kuwait is warmer. Sounds like the Scorpions worked well for you.

While a grade B might not itself be worse there could be other design compromises you couldn't otherwise decipher. Do you run 100+ MPH regularly?


To be honest, I don't think places like Arizona and Texas are any cooler than Kuwait. But the Scorpions have been excellent, which is why I'm considering another set if I cannot find anything else to try. It's kind of difficult to find tires that are A rated in both traction and temperature...so far, I've found the only other two to be the General Grabber UHP and Toyo Proxes STII.

I do tend to run 100+ MPH somewhat regularly though. Not an every day occurrence, but every other day so to speak.

 

[Hokiefyd]

Pirelli's Scorpion tires appear to be a bit of a "sleeper" tire line, not all that popular in truck culture, but showing pretty well most times they're tested. My boss has an F-150 Lariat with the Scorpion ATRs on OEM 20" wheels, and I was rather impressed with how quiet and comfortable they are. They're quieter than the 17" Hankook ATs that are on the '05 F-150 we use as a work truck.

 

[CapriRacer]

Originally Posted By: Falcon_LS
....

To be honest, I don't think places like Arizona and Texas are any cooler than Kuwait. ...


Every time I look up temperatures, I come away with the following:

The hottest spots in the world are in the Middle East. They are a step up from Arizona. Texas is a step down from AZ.

No matter how I slice it, you should consider Kuwait to be a very severe service area for tires - more severe than Arizona and Texas.

 

[Falcon_LS]

Originally Posted By: Jason Adcock
Pirelli's Scorpion tires appear to be a bit of a "sleeper" tire line, not all that popular in truck culture, but showing pretty well most times they're tested. My boss has an F-150 Lariat with the Scorpion ATRs on OEM 20" wheels, and I was rather impressed with how quiet and comfortable they are. They're quieter than the 17" Hankook ATs that are on the '05 F-150 we use as a work truck.


Yes, they've actually been very good. I over inflated them, so the centre wore out a bit more than expected, but even with the mileage on them, they are amazing tires. I hope the price hasn't increased much over the past two years, so I can opt for another set.

The Toyo Proxes ST is also looking attractive right now, with excellent wet and dry traction ratings...supposedly better than the Scorpion STRs based on the reviews I've read. Although there's also the complaint that they do not last too long, and they have a directional pattern...which means I cannot rotate them diagonally. Then again, they are V-rated and so long as I can get 100,000 km/62,500 miles out of a set, I'm a happy camper. Not too shabby at $480 a set, either. Will find out how much the Pirellis cost, and then come to a decision.

Originally Posted By: CapriRacer
Every time I look up temperatures, I come away with the following:

The hottest spots in the world are in the Middle East. They are a step up from Arizona. Texas is a step down from AZ.

No matter how I slice it, you should consider Kuwait to be a very severe service area for tires - more severe than Arizona and Texas.


Very valid point actually. I keep reading tires should be replaced every 6 years, even if they look good, but I personally do not keep a set of tires for more than 3 years over here. I try to run higher pressures as well, so they run cooler, but running the maximum cold inflation pressure isn't exactly easy on the suspension, tire life, comfort, etc. either. I've found the best combination for my vehicle to be 33 PSI front and 36 PSI rear (both cold).