I took the advice of many on this board and filled up the crankcase with M1. In this case it's 15w50 in my 1996 Saturn SL2 that has 88K/miles. (I found a 5qt jug for 18.88 at the local WalMart) I was using Chevron Supreme 10w30 prior to this and thought the deal at WalMart was too good to pass up. The drains prior to this one had Neutra to clean things up during the last 300 or so miles of the oil's life. What I've noticed so far: --Engine noise is noticeably reduced at all speeds. --The Noise,Vibration, and Harshness at idle has been mostly eliminated. For Saturns, I find this amazing! The rear view mirror no longer vibrates to the point of everything being blurred. --Increased power. Yes, increased power! I was surprised at how it seemed to have more punch. I really thought it would go down with the heavier weight oil. --MPG? Don't know, only just changed it yesterday. Still to be determined. What is the cold-cranking spec for this oil? I wonder if this oil could be used most of the year 'round these parts. Overall, I'm really impressed with how this oil raises performance a notch and quiets things down. I better get to WalMart and grab a few more 5qt jugs before the prices go up! My $0.02.