Oil recommends for COLD weather
IF you are unwilling to mix oils (which many are, but usually NOT for good reasons), then you cannot go wrong with the Mobil 1 0W-30 AFE, or IF it stays VERY cold ALL winter, their 0W-20 AFE, or EP.
The Amsoil SSO 0W-30 mentioned above by redtan is also a good oil, and is also thinner than the GC 0W-30, with at least a slightly higher VI as well.
There are NO very high viscosity index 30 weight oils on the market, and the only way currently to get one would be to mix oils as I do (a sky high VI insures a thinner oil at ALL start up temps, within a given HTHSV range).
An example would be; 2-2.5 quarts of Mobil 1 0W-40 (185 VI), mixed with 3.5-4.0 quarts of one of the high VI, car manufacturers' 0W-20 oils (Mazda Genuine high moly Motor Oil 0W-20{221 VI}, Toyota Genuine Motor Oil 0W-20 {216 VI}, or the harder to find, and more costly, Eneos Sustina 0W-20 {229 VI}.
This yields ~ a 3.0 HTHSV, over 205 VI oil which should have NO problems getting quickly up into the heads/valvetrain, even in Arctic Circle type ambient temps.

I personally use 2 quarts of Red Line 0W-40 (190 VI), mixed with 4 quarts of the above mentioned Sustina 0W-20 (229 VI), to give a VERY high VI, ~3.0 HTHSV oil, in the winter, with more of the Red Line for summer.
YES, this IS costly, but I live for oil overkill!
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That's what I recall from my research a long long long time ago. (I had the fortune of moving into a heated garage shortly thereafter.). Now, I'm contemplating running on low oil for a while to see if I can gently wear out the engine - in hopes that I can then get a rebuild (with more power) approved by my residential budget committee...







