Another winter tire question

[krown]

Well, I made the jump from a 2012 750i M-Sport to a 2012 (Canada) M5. The vehicle comes standard with the 20" rims. My question is can I use my existing winter tires on the 750i on my new vehicle? This would save me having to buy a new set of winters, since the ones I have are only two seasons old.

I am currently running:

Bridgestone Blizzak LM-60 95H
245/40 R20 x 4


Thoughts?

[bobblehead]

You can. But it's not the optimal sizing.

265/35/20 square setup would be a bit more ideal for 20"

[krown]

Thanks for the reply. Since it isn't optimal, what would be the consequences of going with this tire size?

[bobblehead]

since the 245/40/20 is still within acceptable variance tolerance, your only concern is the speedo is bit off. Speedo will show 1.5km/hr slower for front; 3km/hr slower for rear.

In the worst case scenario, if the improper tire size is selected, the result could be:
1) wrong speedo reading
2) rotational variance could set off car's main ecu
3) proper braking ability
4) tire is rubbing against the wheel well when turning which over time may lead to tire damage & excessive wear
5) handling may be affected which may result in the car pulling to right or left

[krown]

Great. Thanks for your help!