The recall of the GM engine and the 'warranty' fix of going with a heavier weight oil got me thinking. I've got a '19 Ram 1500 with the 5.7 Hemi, 90K on it now and it calls for 5W-20 oil which I've always used. Seems as if one of the problems with this engine is flatspotting the roller lifters. I do an oil analysis every oil change and there's no wear or non to speak of nor particles in the filter.
What's the collective thoughts of going to a heavier oil say a 10W-30 or a 15W-40?. The lighter oils were supposedly spec'd for mileage which I find hard to believe oil viscosity will make a hill of beans difference on a warm engine. My concern is oil flow at lower temps. Summer's not so bad but winters get as low as -10C around here and I don't want to cause starvation issues. Even saying that, I would think there's more than enough residual oil left on an engine to lubricate it during a cold start until the oil starts flowing. Thoughts?