What is the largest size tire than can be ran on the stock rims?

I was thinking about going 245's in the front & 255's in the rear.

Would you have to drop to a lower sidewall series with the larger size?

 

Yup, you can do a 245/45 in the front and 255/45 in the rear. That's wider than stock, but the same diameter so your speedo won't be off, and the traction control will be happy.

 

you can run 275/40 on rears and be ok

 

seriously? where can i find those tires? ive looked for a while but i cant find em. also ive seen that 275's need like a 9 inch wide rim to work, and the rear rims are 8 inches wide.

 

Don't go over 255 on the rear 8" rims. Whoever said 275 likes a bulging, unsafe tire.

 

The 275 setup is popular for autocross, but typically those tires are changed out every few months anyways and not driven on the street. I don't know if you'd have any problems using 275s on the stock wheels for street use, but I highly doubt you'd see any difference vs. a 255. Go with the 245/255 setup as someone mentioned. Do a search for 255/45-17 or 245/45-17 on Tirerack.com or tires.com and see what comes up.