Been running 15W-40 rotella diesel
oil for years. I have a hydro roller motor. I also run 1 bottle of either EOS
oil suppiment or Lucas
oil additive. HVHP oil pump with #100 spring. Have a accusump to start motor, no dry starts. Let motor run for 1-2 minutes without any change of throttle until some heat is in the oil and the pressure comes down to under 90 psi off idle. Any good oil will work but remember that they have removed alot of the
Zinc and Ph. to help with wear and tear on the internals. Rick L. Ps I don't believe in syntheics for the extra cost in track cars. Also not looking for every extra HP I can find.