i currently have 235/45/17 tyres on my mags.

will 255/40/17 fit? is 40 the profile? in that case i'm not worried about differences in the speed signal due to the lower profile (semi-slicks for track use)

cheers
Felix

 

that 40 is the sidewall height, 40% of the tread width 255.

 

Yes, those will work, assuming your wheels are at least 8.5" wide.

 

how does that work?

thanks
Felix

 

read here:

http://www.tirerack.com/tires/tirete...l/sidewall.htm

 

thanks

 

Yes 255/40-17 will fit up. Wheel widths and offsets are 9 x 17, 40-50 mm offset; 9.5 x 17, 42-50 mm offset.