Slicks Rules question
 

The short an sweet question:

Obviously when it comes to max, the definitive guide line is the actual measurement of the TREAD and not the nominal tire size stamped on the tire. But could you run a slick with a nominal tire size that is larger than 9" but the actual measurement of the TREAD is in fact 1" smaller than the max?



I'm fighting some wheel size/backspacing, and slick size fitment issues on my fwd car im preparing for stock. Long story short im having troubles finding a combo that will work for me to get the max width in the height that that I want on a 15" wheel that fits under my front fender with no tread extending out from the fender. I have 16" wheels that work offset wise to get a 8.5" slick under there. But in 16" wheel slicks there are alot of 9.5" slicks, but the tread width is only 8".

Here is what the rule book reads:

Street-type or drag slick tires, maximum 9-inch tread width. Tires
may not be altered from tire manufacturer’s original design or
pattern. Size of tire (new) must not exceed 9-inch wide x 30-inch
diameter (94-inch circumference). Tires may not exceed 10 inches
wide regardless of wear. Front tires must have a full street pattern
and must measure a minimum of 4 1/2 inches on ground. Tire tread
may not extend outside fender; maximum clearance between side
wall and body is 3 inches. Slicks permitted on FWD cars. All-wheeldrive
vehicles must have treaded front tires. Recapped/retreaded
tires prohibited. See General Regulations 5:1.

Re: Slicks Rules question
 

There is NO mention of the slick having something imprinted on the sidewall. So yes, as long as you are confident that there is no way an official could measure differently than you; by way of method or tool, then you will be OK.
FYI - The reason they don't go off a p/n is because tread widths vary with wheel widths and wear (tread width can change with wear).

Re: Slicks Rules question
 

Thank you. And also some of the tires im looking at all though they say 9.5 on the them, they are under the 8" tread width section on jegs website.

Re: Slicks Rules question
 

NHRA used to have a rule that you could have 12.5" tread IF it was a treaded DOT tire. Is that rule still in place?
If so, that might give you some leeway using a DOT drag radial.