Yes it's another oil thread (sorry). I've read a lot of the others, and there always seems to be a lot of fretfulness over getting a "0Wxx" or a "5Wxx" and is it a 30 or 40 or 50. Always living in temperate states (TX, CA, HI), I've pretty much stuck to good old 10W30; clinging perhaps to the brouhaha a few years ago over the higher spread between numbers and polymer additives failing (some/many of you may not remember that.. 
).
Of course, I use synthetic now and all that stuff may be academic, but I still stick to the 10W30 and the lowest spread between numbers (other than a single vis). It's also M1's best seller (not that that's necessarily a testament to wisdom). If I moved up north, then I'd probably use 5W in the winter time. Also, the M1 10W30 gets a "energy efficient" rating, with special friction fighting additives, for whatever that's worth (little better gas mileage I suppose). Anyway, for fellow posters who live below the Mason Dixon, I think it's a good choice for year round use (unless you live in Desert Valley or AZ..).
).Of course, I use synthetic now and all that stuff may be academic, but I still stick to the 10W30 and the lowest spread between numbers (other than a single vis). It's also M1's best seller (not that that's necessarily a testament to wisdom). If I moved up north, then I'd probably use 5W in the winter time. Also, the M1 10W30 gets a "energy efficient" rating, with special friction fighting additives, for whatever that's worth (little better gas mileage I suppose). Anyway, for fellow posters who live below the Mason Dixon, I think it's a good choice for year round use (unless you live in Desert Valley or AZ..
).
