best 20w50 motor oil for 1978 porsche 924
Before testing this oil, I never realized how much old-school protection was slipping away in my vintage 1978 Porsche 924. Switching to the Castrol GTX 20W-50 Conventional Motor Oil blew me away—its high zinc and phosphorus levels kept my engine silky smooth under tough conditions, even during spirited drives. The thick, tough film it maintains … Read more