[Humdingah]

Did an oil change here in Denver last week and it was a similar circumstance...it had been hovering around 0-degrees the night before and after letting the truck idle for about 5 minutes I yanked the drain plug and the 5W-30 was about the consistency of maple syrup. Only drained about 1/4 quart that way and plugged it back up before letting it idle for another 20 minutes to warm everything up.

It's no wonder that -15 would cause things to be a little 'slow.'