Straight sae or multi-grade ? Will a heavier straight sae rob horsepower ?
Thanks Pilot, They previous owner only ran delo 10-40 I don't believe the tolerances and the specs. in 1988 called for a multi grade. With the zinc changes these days I run Royal Purple 40 sae in the summer and 30 sae in the winter. yes i do warm the oil up for sure, I hold a good 70 psi with both apps. I just couldn't take the guage going from 40 to 70 with the multi grade summer or winter. Thanks again for your input.I should stay out of this one but here we go!! Yes, heavy oil robs HP, pre-heating oil is always recommended for racing applications no matter what!! I'm not in favor of multi-grade oil myself, if I lived in Canada or Alaska and ran my stuff in the cooler months I might consider it. In the days of qualifying, Pro-Stock drag cars, NASCAR stuff, sprint cars, etc., we would run very light weight oils all in straight grades.
Just watch your oil pressure when your engine is cold and don't romp on it until the oil is warmed up.
MY OPINION ONLY!!!!!!!!!!!!!!!!!!!!!!