Scotty back in the early 90's Quaker state motor oil was pretty popular. My volvo dealer used it. Now I hear dealers use basically what their suppliers carry, and castrol is used by many dealers now. I know you like castrol. What's your opinion of quaker state? Still as good? Thanks.
I believe shell oil now owns them, and they make quality oils. The original quaker state oil was the best over a hundred years ago, cause penn oil had good qualities. but those days are long gone with oil additive packages. Everyone uses a mix of blend oils from various sources and various additives