Automobile(s): Cadillac 78 Seville, 78 Coupe de Ville, 92 Sedan de Ville
Re: type of oil
Modern oil doesn't have enough zinc to protect your cam and lifters. You can google it but most old car drivers run some kind of diesel engine oil like 15-40 or 5w-40 synthetic unless you have to run catalytic converters.
I use the car very little. Probably less than a 1,000 miles between oil changes. Would I still need the additive? I heard that the zinc content in modern oils would be enough for lower miles between changes. Any take on this?
Modern oil with the lac of zink will not protect the metal to metal contact of a flat tappet cam.. you need the zink. They slowly took it out to reduce emissions.. Do some research , see what the flat tappet cam makers are telling you to do.