humor me. I'm looking at new rims for my 1LT, and I'm looking at a couple websites, and theres a reference to offset (I also believe its referred to as backspacing). I understand what offset is, but don't know what to look for.

brand "A" may offer +42 offset, while brand "C" offers 0 offset.

which is right for the HHR?

 

You should have a 38-42 offset. Mine are 38 and I have had no issues with 18's and slightly taller tires. 7.5" width/./

 

Offset is different from backspacing. Offset is how far the mounting surface is "offset" from the centre of the rim. Backspacing is from the mounting surface to the inside face of the rim.

 

This link should explain some things.

http://www.rims-n-tires.com/rt_specs.jsp