is there an 18" wheel & tire combo that WORKS on an HHR?
 

Would like a set of 18's if they will fit, and I have got my eyes watching for SEVERAL other vehicles with correct 5x110 bolt circle (yes I know offsets are also critical). But the bigger issue seems to be overall height. Enlighten me plz fellow HHR owners. WHAT WORKS?!?!?!

The SS has 18 inch wheels

HHR SS's came with 225x45x18 on 7.5 inch wide rims. That size specs out to about 25.9 inches tall. The tallest tire you can use is about 26.3 inches. Any taller will hit the bottom spring perch of the struts.
LS, LT's and SS's all share the same suspension geometry so yes, 18's will fit.

This is the clearance I had when I updated to 26.1" tall tires........Close enough imo..

https://cimg7.ibsrv.net/gimg/www.che...31bf95e9fb.jpg

Not to hijack this thread too badly. But has anyone run spacers to put the wheel closer to the fenders. As to say a wider looking stance

Be careful of putting your tires out there, my stock OEM steelies, are 42 mm offset and clear the body , but my WV rally rims are 35 mm offset any that 7 mm is enough to touch the tire to the wheel opening lip

https://cimg8.ibsrv.net/gimg/www.che...a4b86cb91.jpeg
7 mm and the tire rubs the fix, I replace the 2 inch lowering springs with 1 3/4 inch lowering springs .
https://cimg1.ibsrv.net/gimg/www.che...5c0558aef.jpeg
The other side. Yup a rub. But only with a passenger in the rear seat

Whoa, Surprised that it rubbed. Looks like you have a lot of height clearence

The HHR is on jack stands in both pictures.

I think adding additional neg offset would be harder on the vulnerable wheel bearings as well. But would look cooler.

Mine is lowered/ leveled in rear, so I'm not gonna mess with the possibility of scrubbing the tires.

you are correct sir
best is to keep things within a 2-3mm range, so if stock is 42mm offset, I wouldnt go more than a 38mm offset.
while some people will say 4mm isnt much of a change, you need to remember the engineers who designed the car are using very specific geometry, and most parts are provided by "the lowest bidder" for the contract.