Any thoughts on using Penzoil 15w40?
#31
Originally Posted by anonymousagain
Chris - you're referencing the Multi-grade chart, not the Synth chart
Consider that it ISN'T on the Synth chart, because there's more flow/better oiling from the lower 5w/10w weight and the 50 higher/hot number is still covered...essentially the Engineer is saying, "Why not get better flow (especially cold/startup) with the same hot 50 weight coverage".
Don't get me wrong, 15w-50 M1 - great oil, although IMHO a 5w makes more sense for cold/startup coverage.
Consider that it ISN'T on the Synth chart, because there's more flow/better oiling from the lower 5w/10w weight and the 50 higher/hot number is still covered...essentially the Engineer is saying, "Why not get better flow (especially cold/startup) with the same hot 50 weight coverage".
Don't get me wrong, 15w-50 M1 - great oil, although IMHO a 5w makes more sense for cold/startup coverage.
#32
IIRC, Mr. Hillary clarified not too long ago that a quality 40w Synth (eg, RotellaT 5w-40) has the same hot viscosity as a 50w (eg, M1 15w-50) at ~200deg normal oil operating temp...not sure how much hotter it'd need to get before a 50w is beneficial, or even if it could ever get there
[FWIW - Walmart <by me at least> carries RotellaT 5w-40 Synth for $16/gal and I've had good pressure and temps even on 100deg days with AC. I would never have tried it if Mr. Hillary hadn't pointed it out as a "best of". Anyway, it seems like a bargain compared to M1 @ nearly $7/qt.]
[FWIW - Walmart <by me at least> carries RotellaT 5w-40 Synth for $16/gal and I've had good pressure and temps even on 100deg days with AC. I would never have tried it if Mr. Hillary hadn't pointed it out as a "best of". Anyway, it seems like a bargain compared to M1 @ nearly $7/qt.]