Mark A wrote:

>>I realize there are different parameters but within a type and brand,
>>I'd think a tire rated for 80,000 miles would cost more than one rated
>>for 40,000 miles, is that not so?
>
>
> Actually, not necessarily true. Many very high performance tires do not have
> particularly good tread ratings. Generally the higher the speed rating
> (tires are have speed ratings such as S, H, V, etc) the less the tread life.
> That is because a tires ability to run at higher speeds depends partly on
> using a softer tread compound that wears faster. This is very evident in
> motor sports racing, where a very soft, but very high performance tire will
> need to be changed several times during a 500 mile race.

Actually - how hard a rubber compound is doesn't necessarily affect
how it wears. I was at a Firestone dealer getting an alignment and
looked at their Indy car tire display. They had a real used sprint
car tire and a new one. Those suckers were hard as a rock. I'm told
they have to warm up and soften for optimum grip.

> Some people think that an S speed rated tire is sufficient because they will
> never exceed the 112 mph maximum speed rating for an S rated tire. However,
> an H, or V rated tire will almost always have superior handling, breaking,
> etc than a S or T rated tire (all other things being equal).
>
> However, there are some newer tread compounds that provide a better balance
> between performance and tread life, but they are more costly than
> conventional tread compounds. But even these newer compounds will usually
> not last 80,000 miles in a high performance V rated tire.

Low wearing summer car tires meant for high performance driving are
often harder. I know it sounds counterintuitive. A lot of summer
tires will get way too hard even in dry cold weather conditions to be
safe. During summer conditions, a harder rubber compound (within
reason) will grip/handle better, and won't necesaarily last either.