[GlacierF32]

Will 245/40/R18 square fit on my 2015 RWD 435i M sport as a winter tire setup?

[visionaut]

I run 245/40-18 square as my winter setup, on 18x8 et29 wheels, on my 435iX GC. So they’ll fit depending on your wheels (width/offset).

[johnung]

Originally Posted by z33alex

Will 245/40/R18 square fit on my 2015 RWD 435i M sport as a winter tire setup?

I run 245/40-18 as a summer tire on 400M wheels (18x8.0"). I went down to stock size 225/45-18 for my winter tires because several people warned that wider tires tend to float over snow rather than cut through it under control

[Canadared]

You want narrower tires for the winter to cut through the snow, 225/45/18 is perfect

[visionaut]

I’ve found 225 to be too narrow - in summer & winter - on my 4 for me. I think it’s undersized for the car’s size & weight. There’s too much understeer, and not enough grip when it’s cold, wet or dry, or on ice.

I also don’t have constant snow - it’s only like 20% of my winter driving. And there’s lots of dry funner days.

Thus, my choice for Michelin PA4s in 245/40s...

[Canadared]

Without knowing where the OP lives I have to offer info based on where I live and it happens I live in the snowbelt (Southern Ontario). I don't know why you would be running 225 squared on a summer set....... but for the days of heavy snow I'm not taking chances so I run a narrower tire. My commute is 80% highway, 50km each way.

I run Pirelli Winter Sottozero 3's so I can enjoy the dry days too.