Any advice?
Valvoline VR-1 20W-50 in my coupe
With high zinc oil, factor in taking your plugs out every other month to clean them because zinc buildup will cause electrical continuity that degrades the spark. Don’t believe me? Check them with a multimeter.Use VR1 20/50 in the Packard. It has a very high zinc content for an off the shelf oil and is good for valves of older vehicles. I plan to start using it in Vern and Athena.