This was my "experiment" with Valvoline straight 20 in my Chrysler 300M which is spec'd for 10w30. Oil saw the gamut of temps from the mid teens to 100+ and 90% of the driving was short trips of under ten miles.
Terry said he's very impressed with this Valvoline SM straight grade formulation. Wear is down across the board, especially bearing wear. (Confirmation that no more bearing rattle on start up with straight weight actually means something?) Vis is a solid 8.5, which is what this oil starts with, so no shearing took place at all (thanks to no VI improvers).
I think this UOA confirms my suspicion that if you live in a moderate climate, and your engine is spec'd for 5w20, 5w30, or 10w30, then straight 20 is a viable alternative.
NB: Previous UOA was Havoline 5w20.
Terry said he's very impressed with this Valvoline SM straight grade formulation. Wear is down across the board, especially bearing wear. (Confirmation that no more bearing rattle on start up with straight weight actually means something?) Vis is a solid 8.5, which is what this oil starts with, so no shearing took place at all (thanks to no VI improvers).
I think this UOA confirms my suspicion that if you live in a moderate climate, and your engine is spec'd for 5w20, 5w30, or 10w30, then straight 20 is a viable alternative.
NB: Previous UOA was Havoline 5w20.
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