47 for the stock 15"
41 for M3s
Right now I've got 245/45/16 with a 37 offset and no problems in the front. In the rear with a couple people in the back it scuffs a little bit the BFH has been working that out.
With a 40mm offset you shouldn't have a problem with 245 all around. Maybe a spacer in front... but spacers are easier than pounding fender liners.
Kevin (President TBEA)
"WAAAAAAARRRRRIORS, come out to plaaaaay."