I don't exactly know how to understand offset. I don't know bigger or smaller the number does what? I see everyone goes with a 39 offset. The wheels on my car are 42 offset. I think this is why i rub so much..
14" x 6" +39MM is stock for the 165. I've run 15" x 7" with +45 offset and had to use 5mm spacers to stop the rubbing. They were 1" wider, so you have to take wheel width into consideration too. Clear as mud?
basically, offset is how far off the middle line of the rim, the back face sits.
so, positive offset, sits forward or outboard of the middle line, and negative offset is pushed inward of the middle line. and 0 offset is directly in the middle.