Engine Oil

[duke36]

Originally Posted by Oldgearz

Hate to start WWIII, but is PennGrade SAE 40 high zinc and phosphorus used by Aers very much?

See the "Microlon" thread. The use of zinc has been debated but found to be beneficial in classic and horiz. opposed cylinder engines. Shell Rotella used to have higher levels of zinc but the levels supposedly have been reduced and possibly due to the adverse effects on modern catalytic convertors. Suggest reading up on adding ethanol stabilizers to the modern fuels, another subject of debate affecting engine performance..