19.5 tires and their speed ratings.

[GShail]

The speed ratings on the 19. 5 tires I have been considering are only maxed at 75 mph. Is this a realistic rating or is it artificially low because 19. 5's are primarily used in commercial applications? I don't tow fast myself personally, but am worried that on occasion my employees may. We do live in some very wide open country. A Pirelli Scorpion ATR in 235/80/17 for example is speed rated at level R - 106 mph. But all of the 19. 5's are rated at only 75 mph. I sure do see enough semi's speeding well past 75 mph, especially in Wyoming out there on Interstate 80.



How fast can you run a 19. 5 tire?

 

[kenny61]

I've run em as fast as my truck can go never had a problem. This is not every day or for hours at a time either. I've cruised 75 - 85 mph for a few hours with no problems felt em afterwards they dont heat up

 

[FordCummins]

The tires are rated at the "lower" speed of 75mph because that speed rating is calculated when the tire is at its maximum payload. I cant remember offhand what the max payload of one of my 245/70R19. 5s is, but I think its in the 5500 to 6000 lbs range. I am assuming your tires will never see that kind of weight in total, and therefore the heat generated will be nowhere near what the tires have been designed to sustain.

The only downside to running at higher speeds with the 19. 5s for long periods of time is faster tire wear.....

 

[GShail]

10-4, I think you are making sense.