Question -245/40R18 with 513M wheels?

[basem3///]

Hello,
First off, thanks to everyone for all of the great info on this forum.

I came across a pretty awesome deal on winter tires. Nokian WRG3 245/40R18 off an M5 with about 3000k miles on them. Everything I read says 245/45R18 is the tire of choice.

I'm looking at picking up a set of OEM 513M and want to know if I can run these 245/40R18 without any issues. 513M rears are bigger. Can I run square with these tires and wheels? Ohio winters, but if it is snowing at all the M stays at home. More for cold dry days and the off chance I'm caught in the snow.

Any advice is much appreciated. Thanks!