[dhirm5]

Stock offsets for the 20" wheel are:

9Jx20 ET34
10Jx20 ET34

Most people use 12mm spacers in back for perfect/flush fitment, so the ideal offset for a custom 20" wheel of the same 10" width would be 22 (fixed). I think this part is solid (but correct me if I'm wrong).

Now - let's say I move up to an 11" width in back. Since 1" = 25.4mm, an 11" wide wheel would stick out past the stock 10" out the gate by half of it's width, or 12.7mm. So a 20" wheel with 11" width using an offset of 34 would actually stick out FURTHER in back than the OEM 20+12mm spacer by 0.7mm.

Therefore the ideal offset, being slightly conservative to avoid rubbing, for a 20x11 wheel, would actually be 35, which would tuck under by 0.3mm vs an OEM 20+12mm spacer.

Does all this sound right?

Once this is confirmed (or corrected), I can figure the front and finally consider myself as having fully understood offsets.

Thanks