Perry,
The 255 or 295 number is the measurement of the widest part of the tire in millimeters. The 295 mm or 275 mm tire fits nicely under the rear fender of a Cobra but they are a little large for the front. My 275 mm wide front tire is about an inch outside of the fender flare. The usual front tire on a Cobra is a 245 mm. To me this is a little too small and I have trouble getting balanced handling. The 255 mm wide tire should be about perfect, with the widest part of the tire even with the edge of the fender, the height (60 aspect ratio) exactly 1 inch shorter for a nice rake and better aerodynamics. The tread width is less than an inch narrower than the rear so handling balance should be attainable.
There have been NO street tires speed rated better than "T" (118mph) available for a while. With the motor you have, that can happen in a matter of seconds coming up the on-ramp of a freeway. The "H" rating means the tire has been tested at 130 mph for hours. That's the kind of quality I want to have under me when the scenery start blurring!
This could be very good for us. Way to go Kumho!
Check out:
http://www.tirerack.com/tires/Spec.j...odel=Ecsta+STX
Paul