I think there should be a sticky for what diferent size tires other than the 225/40 R18 can fit with our stock 18s. Has anyone else tryed a different size on our rim? Just will help out some of us on buying all season or winter tires. I am going for safe but cheap.

A lot of people on this board install tires that are too wide for the wheel. Ideally I would like to install a 235/40/18(.5 tallr and 10 mm wider) tire however all tire manufacturors suggest using a wheel that is at least 8 inches wide for a 235/40/18. Our Stock 18s are 7.5 inches wide.

Other options
225/45/18 Stock HHR SS tire size (Larger diameter)
215/45/18 Stock SS/SC tire size

That is about it from what tire rack is showing.