Genny oil

Synthetic oil is great. BUT, Synthetic oil will go thru minor gaps in various seals that regular oil will not. So, if you have an older engine and have no leaks or just a very minor leak, then start using Synthetic, you will have more leakage. A Mobil engineer told me years ago that it is best to start using Synthetic when the engine is new. NOT a good idea when an engine is used and broken in. Doug