Lizard928

if 7.5" front you can run 245/45R17s, if you have a 7" then 235 is the max front width.
For the 9" rear 275 is max.

redpathtribe

FWIW... as Matt mentioned, 265-40's are rare, only 5 mfrs. listed on Tire Rack. But, Michelin does have them in their PS2's as Glen mentioned, VERY nice tire, but expensive. Many more options in either the stock 255-40 size or 275-40 size. Also, FWIW, and this took me a while to get there, remember that the tires are the ONLY thing holding you to the pavement. Don't try and go too cheap, especially in a legitimate supercar like a 928. You don't want to have tire "issues" at triple digits or in high g turns...

Daymon66

thanks guys. i appreciate your advice and experience.
i don't like saving money on anything that pertains to safety and vehicle integrity.

there are some cheap tires available but i'll pass.