[RaceProEngineer]

Noel and all,

Reading your post about street tires brings up one other very important point. Stating the obvious - street tires, regardless of their speed rating, are not designed for racing. But their "UNsuitability" is not readily apparent.

When asked to provide extreme traction, street tires not only vary widely in their ability to grip, but are quite inconsistant within themselves from moment to moment. On the track, these characteristics can translate into very "tricky" handling. For example, if your rears have a substantially higher friction coeffecient that your fronts, you are going to have "your hands full" under threshold braking. Similarly, if during the last 4 laps the driver has been able to "plant his foot" before the apex of Turn 7, but THIS time doing so produces severe understeer . . . . . well, you get the point.

Race tires, in general, provide much higher levels of traction than tires made for the street. But equally important, the best of the racing rubber offers supreme consistancy, which in turn inspires confidence, which in turn translates into lower lap times, etc.

None of this becomes apparent until one starts driving the car at, or near, its limits!

Ed