CharlieS
GOLD Star
Thanks for explaining that. I don't know as much about these details and always learn a lot when I read your well thought out explanations.It's not a matter of driving over 100 mph, it's a matter of safety margin when travelling at legal highway speeds under adverse conditions (like summer heat in the desert). As ambient temp rises, tires have a harder time dissipating heat. This leads to heat buildup and potential tire failure. One of the criteria used to meet any given Speed Rating is a tire's ability to dissipate heat. A tire with a 130 mph Speed rating will be able to dissipate heat better than a tire with a Q or R Speed Rating.
Thus why I said I would be "more comfortable" on the highway with a tire that has a higher Speed Rating.
Doesn't necessarily have to be desert heat conditions, either. Suppose, for whatever reason, one of your tires is running a little low on pressure. A tire with a higher Speed Rating would be more forgiving of the heat buildup caused by the low pressure than a tire with a lower Speed Rating.
Given the choice, I'm all for more safety margin.
But hey, this is the internet, feel free to make fun of this as well.
HTH