I am curious to know what exactly is tested when a speed rating is assigned to a tire? is it the average speed the tread starts to seperate, the max speed the tire will hold traction or what? BF Goodrich has a 295/50/16 Radial T/A tire out, but it is only rated at 112 MPH (S Rating). Sounds like an awful waste of tire to make a beefy tire than can't handle low 12 second passes at the drag strip. is the speed rating arbitrary, or is it something to really worry about and take into concern when racing at high speed? I figure I'd post it here since there is no tire specific forum. cheers.

 

speed rating is given for the maxium speed a tire can be operated at for a consistant period of time (1 Hour) so if for example your tires are rated for 112 MPH then if you operated them above that range for an extended period of time, they'd be hooped.

Though if your doing twelve second passes, maybe you should consider investing in some race tires.

 

this isn't to make a decision on tires, I've got KDWS and I like them a lot, just wondering why such a wide tire would be so useless lol. I wish BFgoodrich made 295/50/16 KDWS

 

What g ride said is true. In drag racing though you really don't have to worry about it too much because you'll only be at speed for a few seconds. The BFGoodrich drag radials are only R rated to 106 mph, yet they have seen over 180 mph in the 1/4.