The
Merkur Encyclopedia has a pretty good table to get you started. Scroll down the left side menu to the link that says "Wheels." It'll give you offsets for Merkurs (all at 41mm) and Tempos (42mm). What it doesn't tell you is that our stock offset is 40mm.
Sounds like if you just want to run narrow winter tires, you should be fine with any stock XR4Ti wheel.
