[Zamorskii]

I tried ordering Blizzaks from a local tire shop in 225/45/18, but they cannot get them, and given they never told me about it, the shop is willing to match their price on some Michelin Xi3 winter tires, but in a narrower 215/45 profile.
The savings come to about $40 per tire and in general I think Michelin is a better tire, but I am concerned about the handling and speedo accuracy since this is not the "approved" size for F30.

What do you guys think, shall I go for it, or order correct sizes from tirerack or someplace else?

[JYohay]

Sorta hard without telling us what width wheels you have.
You typically want to go 1 width down and 1 height up for winters (height is a ratio of the width, not actual measurement.
I'm assuming your stock tire sizes are 245/45
You could get 215/50 even.
Speedo accuracy will only be about 1mph off, and it shouldn't matter since speedo already reads 5-9mph above actual speed

[Zamorskii]

I now have a sport line with 225/45/18 all around. It's a RWD car also.

[.BMW.]

No problem to run that tire size. But if your wheels are 8" wide the tires will look a bit stretched.

215/45-10 is only 1% shorter than OEM so that is no big issue.

[casualDIYer]

Originally Posted by Zamorskii

I tried ordering Blizzaks from a local tire shop in 225/45/18, but they cannot get them, and given they never told me about it, the shop is willing to match their price on some Michelin Xi3 winter tires, but in a narrower 215/45 profile.
The savings come to about $40 per tire and in general I think Michelin is a better tire, but I am concerned about the handling and speedo accuracy since this is not the "approved" size for F30.

What do you guys think, shall I go for it, or order correct sizes from tirerack or someplace else?

For winter, a smaller wheel and narrow tire has always worked for me. For 3 seasons of the year its 225/45/18 but for winter 215/60/16.

Yes, even 16s will fit a 320 and a 328 (not a 335) but do not use inner wheel weights. I did and had to remove them and now I have to get the wheel re-balanced with rim mounted weights. ~sigh~

I have the X-ice3 and they are excellent on ice. The blizzaks are great in snow and slush but they are basically an all-season tire covered with very sticky rubber. Season 1 and 2 are great. Season 3? You've got an all-season tire.

[Ih8usrnms]

the tire might look a bit stretched winter tires tend to run narrow. But other than that you should be fine.