Rear tire width requirements in relation to HP?

Woods74 said
One of the reasons I went with 17x8 is the stickier tire compound, if you look at the UTSG grade for anything besides a drag slick in 14 and 15", you'll see nothing less than '400'. Which for the most part, translates to 'buy our hockey pucks designs from the 80's that we are beating to death...'

I'm still trying to figure out why my new tech '400' grade tires out stick my old '400' 2:1...

I guess tire tech has come a long way since the BFG T/A.

I assume you mean "UTQG"? Treadwear numbers indicate nothing regarding traction or rubber compound. And they only give some idea as to how long a tire will last. Per Tire Rack:

"Treadwear Grades

UTQG Treadwear Grades are based on actual road use in which the test tire is run in a vehicle convoy along with standardized Course Monitoring Tires. The vehicle repeatedly runs a prescribed 400-mile test loop in West Texas for a total of 7,200 miles. The vehicle can have its alignment set, air pressure checked and tires rotated every 800 miles. The test tire's and the Monitoring Tire's wear are measured during and at the conclusion of the test. The tire manufacturers then assign a Treadwear Grade based on the observed wear rates. The Course Monitoring Tire is assigned a grade and the test tire receives a grade indicating its relative treadwear. A grade of 100 would indicate that the tire tread would last as long as the test tire, 200 would indicate the tread would last twice as long, 300 would indicate three times as long, etc.

The problem with UTQG Treadwear Grades is that they are open to some interpretation on the part of the tire manufacturer because they are assigned after the tire has only experienced a little treadwear as it runs the 7,200 miles. This means that the tire manufacturers need to extrapolate their raw wear data when they are assigning Treadwear Grades, and that their grades can to some extent reflect how conservative or optimistic their marketing department is. Typically, comparing the Treadwear Grades of tire lines within a single brand is somewhat helpful, while attempting to compare the grades between different brands is not as helpful."

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=48