Mark A wrote:
> "ray" > wrote in message
> ...
> > Actually, higher speed rated tires are usually HARDER to withstand
> > the heat generated by sustained high speeds. Race tires are a
> > totally different breed... my drag radials aren't speed rated at
> > all and have a treadwear rating of ZERO and they're technially
> > street legal... but I don't bother because they're so "squishy" I
> > don't feel comfortable driving the car on the street... but they
> > have a ton more grip once heated up versus any regular street tire.
>
> I believe that it is the sidewalls and belts under the tread that are
> harder, not necessarily the tread itself. V and Z rated tires usually
> don't last as long as S or T rated tires, because it is the tread that
> wears.

Like I said - it's counterintuitive. At speed the idea may be to
get optimum grip. A compound that's too soft might get too squishy
at the limits of the speed rating and overheat. A soft compound
might be OK at freeway speeds.

Of course there are no absolutes. What I'm trying to get across is
that harder rubber doesn't always mean worse grip or longer life.