Don't dump the platinums, just get a cheap set of
hotter plugs for winter, then put in the Bosch for the
rest of the year. Yes big difference in crank speed
from 10-30 to 5-30 and even 0-30 Mobil1, in the
super cold I would go with 0-30 , I use 5-30 here
in So. Cal in the " winter" LOL but it does get a little
cold here, several mornings will be frozen here, mostly
it will be about 35-37* and drop in the Mts to 10 - 20