mixing tire sizes..

no, you can put different size tires on and it wont affect anything other than being able to rotate them. I have been running 265 on the front and 285 on the rears for about 2 years now. I just replaced the rears not to long ago and I probably have anouther 5k miles left on the front or more.
 
StangFreak32 said:
i think i would skip out on the nitto and try to find a 255 goodyear tire with the same tread as the stock ones seems to me u would want similar tread for ur tires....course i may have no clue what im talking about :shrug:

as long as you have the same tread on the same axle you're ok. In snow, I would reccomend all the same tread (ideally winter tires)
 
Speed rating check

40th GT said:
I'm thinking about saving some money and getting the 255/45/17 Nitto street radials for the rear, and keep the stock Goodyears up front until they wear out. Is this going to be unsafe for everyday driving?

For everyday driving with some hustle especially in turns speed rating should be real close. If they both are 'V' or 'Z' should be no problem. If the Nitto are 'H' or less and they are on the back the slip angle (grip) of the higher speed rating on the front may cause lower speed ratings on the rear to break or swing out. I would think the blimp guys are Z rated.