[joachimkazmaier]

I am running 225/45-17 on stock wheels, no problem whatsoever. You could run 235/40-17 on stock wheels, but they are really recommended for 7.5" or wider rims. As far as handling goes, without compromising comfort, I have settled fro Pirelli Pzero AS+, which for the Forte is a bit overkill, but I'm amazed how much more precise I steer through quick bends, where before, on the stock Nexen CP671 I corrected a lot. Also, the speedo difference to 215/45-17 is 1.6%, BUT the car comes stock with 16'' and 205/55/-16 and compared to those, difference is 0.4%. Negligible, either way.

 

[joachimkazmaier]

Could it be DANGEROUS (tire getting lose from the rim) If you go wider than 225s en a 17 x 7" ? I mean because its been said here that for 235s you need to go to 17 x 7.5" . The thing is that Im about to put 225s on the 17x7 stock rim, and here in Mexico I frequently get to 100 + mph por 5 or 10 min periods. And I wonder if this might be dangerous. Thanks

No, but it isn't recommended. Also, depending on the tire you buy, it may come out larger or less. My PZero AS are looking narrower than the P7 Cinturato and in fact, they are. So, best go with 225/45-17, they work well. Also, 235/40-17 is really rare, you will not find a lot of choice in that size.