Engine Oil
 

On many forums there are people saying you should use synthetic oil in your classic, while others say to use conventional, and diesel oil. What are your guys' thoughts on Oil? I am about to do my first oil change.

Choice of oil is more religion than science. You will get no useful responses.

X2, other than todays conventional oil should be superior to the oils sold say thirty years ago. That and less expensive than todays full synthetic.

If you want to find all the oil leaks in an older motor, use synthetic. I agree with rocky raccoon.

LOL. This is such a true statement.

The main thing to look out for is using zinc on these because of the cam and rocker style.
https://www.amsoil.com/newsstand/classic-and-vintage/articles/flat-tappet-cams-in-classic-cars/

I am not going to go out and suggest any particular type - buy the best you can afford is my motto, and change it based on your driving habits. But just make sure it has zinc.

Is it? I've been using a 15W40 para synthetic for years and find no particular problems with oil leaks.

I personally use conventional 20W-50 oil.

In the SD I use a lighter weight conventional oil in the winter; helps it to spin better when starting if it is cold.

I could very well be wrong. I've been wrong many times before.

I've been using some sort of synthetic since 1982 which is long before most people were even aware of it. I've found that a tight non leaking engine won't leak with synthetic and an engine that leaks with regular oil will also leak with synthetic. Oil type proves nothing except that leaky engines leak oil.

Part of the issue is actually how well synthetic cleans... so it'll clean the gunk off the outside of your engine that built up from leaking conventional.

Just observe the second number in the weight the car calls for and you will be fine.

I think a lot of people like to blame their lack of desire to change a front main seal on their one time usage of synthetic oil.

The detergent package in any oil isn't like a bar of soap where it will clean all of the grease and dirt from your hands. In this case it will only clean what's loose inside your engine and if everything is baked on old crud it won't touch it at all.

Synthetics hold dirt in suspension much better than regular oil and will keep your engine clean inside even over long change intervals. I've been using various brands of synthetic in my farm equipment for the past 30 years and I've never had an engine failure. My 230SL has run synthetic in all applications for the same 30 years and it runs great.

Your mileage may vary.

After buying a new head from them Metric Motors advised me to use Castrol GTX. It was cheaper then Delo, so I followed their advice.