[HDEddie1]

Asking for opinions on changing from staggered to square tire set up:

I have an incoming 540i M Sport that is wearing stock 19" wheel/tire set up at 245/40 and 275/35 19" run-flat, F/R 8"/9" wide , ET 30/44 respectively.
I'm thinking of changing out these wheels to BMW wheel 647M (see attached) 19" 8.5", ET 25 all-around, for both front and back. In addition, I would wrap them all in slightly bigger 255/40 19" non run- flats (yes!).

Basic calculator check shows rolling diameter difference negligible on speedo. The front wheel will stick farther 11.4 mm or almost 1/2" and the rear wheel about 12.7mm, a tad over 1/2". The biggest notice is the new rear wheel, which with the ET 25 offset and a bit narrower than the stock wheel is almost 1" farther from the suspension strut.

I'm doing this for: a) looks (not wild about the stock M sport style 664 wheels), b) wanted the wheels a bit more flush with the fenders without the use of spacers, c) maybe a tad more "cushion" staying with a 40 aspect tire (instead of 35 or 30 profile), d) and a bit more neutral handling afforded with square set up.

OPINION: Aside from skinnier appearing tires when viewed from the rear of the car, Im I doing something crazy or missing something here? Thanks!