225/45/18 on 18x7.5 @ ET45 will be super tucked, but it'll fit. 12.5mm or 15mm spacers can "fix" the tuck to "ET32.5 or ET30 however setups like this just doesn't sit right with me, personally.
the B58 is a powerful engine. idk why BMW continues to use 225 widths on these cars. well, i do know why, but still...
i suggest stepping up to a 255/40/18 square setup on 18x8.5 ET35 rims, there are many to choose from.
this is what i'd get. 18x8.5 ET35(18.8lbs) Aodhan AH-11 Matte Black on a summer or all-season 255/40/18 that fits your budget.
https://www.aodhanwheels.com/collect...43678917886211