[AdamIsAdam]

Originally Posted by Formulajones

Again, you have to look at the pour values if you want a real look at the cold operating temps. Not all 20w-50's are the same, not even close. If Butler recommended that viscosity for your engine, then go through the list and find your favorite brand that has a pour value that works in the climate you live in.

There are a few good 20w-50's that will work in extremely cold temps, and some of the 20w-50 brands are better in the cold than some 10w's in other brands because the additive packages are simply better with some brands. So it pays to look at the pour values.

Originally Posted by Formulajones

Here is a chart that backs up what Adam is saying. First column is 20w-50 oils and their pour ratings. Notice how not all 20w-50 oils are the same.

http://mcgeerf.tripod.com/americansy...coil/id17.html

And based on this chart, even the 20W-50 Valvoline Race dino oil pours at -10*F. And I don't know about you all, but my car is: 1) garaged, which means even if it were -10*F outside, the oil in the engine wouldn't be that cold, and 2) IF IT'S -10*F I SURE AS SH1T AM NOT DRIVING MY PONTIAC!

Formulajones, what is your take on the "ash" rating on that chart?