PennGrade 1 Adds Full Synthetic Oils: What 5W-30 vs. 5W-40 Means for Boosted and Track Cars
PennGrade 1 has added a new full synthetic high-performance oil line. Here is what 5W-30 vs. 5W-40 really means for boosted, high-RPM and track-driven engines, and why oil temperature, clearances and real data matter more than horsepower alone.