It is always best to keep the offset the same as standard so extra width should be evenly spread on the inside and outside of the mounting surface of the wheel = do not change the offset, which is 25mm=1" for the 122S. It may look graet on your car these wide wheels, but driving is harder.

I had a lot of bumpsteer when I changed the offset to zero on my steel Amazon wheels. My new 6" wheels have standard offset of 24mmm and bumpsteer is a lot less on bad roads. I also have over 1 degree negative camber which will also have an effect on bumpsteer. It all depends where you drive your car. On smooth roads = perfect, no bumpsteer even with offset of zero, but NZ roads are not perfect, lots of uneven areas and even potholes caused by heavy trucks.

Bumpsteer is when an uneven surface steers you 122S off direction and one has to correct all the time which is hard on the arms and steering and suspension components.

http://volvoadventures.com/amazon3.html

Jim, New Zealand