Day: April 15, 2021

Test Results: JEGS, Diamond Fleet, and PennGrade

Samples of the following three brands of motor oils were recently examined by PQIA. Click bottles for detailed assessments. JEGS Full Synthetic Motor Oil 5W-30 API SN, ILSAC GF-5 Hot Shot’s Diamond Fleet SAE 15W-40 PennGrade Partial Synthetic Motor Oil SAE 5W-30

Motor Oils for Classic and Vintage Cars

The Petroleum Quality Institute of America has from time-to-time encountered motor oils containing high levels of a multifunctional oil additive called zinc dialkyldithiophosphate (ZDDP). This additive contributes anti-wear, anti-oxidation, and corrosion inhibition properties to the oil. ZDDP has been used in motor oil formulations almost universally for decades, and oils with high levels of ZDDP are often promoted as being better suited for engines in older cars with “flat-tappet” lifters.