I know I'm asking this backwards, but I can't find a straight answer anywhere (including the [sponsored] sticky here), so I'm throwing this out there.

I found a couple of 18" tires that are in my price range and have a more substantial sidewall than the RS-A. Will this fit an 07 SS?

225/60R18

 

I can't help on it fitting or not, but keep in mind the overall height is more than 1.25" taller on your proposed new size. That'll throw off your speedometer at least 3 mph at highway speed.

Also, I think you'll regret going even more narrow on the tires in case you get that ls4 back to 100% again.

 

This is the tire size calculator that I like to use: 235-50R18 vs 225-60R18 - Tire and Wheel Plus Sizing | Tire Size Calculator

Should have your information already pre-populated.

It looks like the tire is 5% larger overall, and on the SS you are already pretty damn close to the strut plates with the stock tire size.

I would lean towards this tire not fitting.

 

You are a useful chap. Thanks for the link--apparently it's Google-repellent.

Sucks, because these were Pirellis at $110, as opposed to, say, Douglas at $124 for the OEM size. (And after seeing a Douglas with its sidewall destroyed last night, I wouldn't buy those for $24.)

 

Thanks. I try