The Stovebolt Site Forums The Shop Area Engine Shop Best Oil for High Mileage 235

I have an original 1961 Chevy C10 with the original 235. It has 81,000 actual miles. I've put the last 10,000 on it in the 40 years I have owned it. The engine has never been rebuilt. Since I have owned it I have always used a straight 30W Petroleum based engine oil (I live in Texas, so it gets hot). Changing oil and wondered what the current thoughts are for the best engine oil considering age and mileage. There are so many choices and synthetics and blends now. PS, it does not smoke or leak and would like to keep it that way. Thanks for your input. PSS My truck is in the Gallery.

In Fort Worth, I'd continue to use straight 30W and let it be. With 81,000 miles on it, you'll have to rebuild it some day, but if it isn't smoking nor leaking you're in good shape. I would avoid all the multi-viscosity stuff and especially the synthetics.

Phillip I think jon is right would look into the zinc additive zddp for it and keep truckin' ! I bought some additive at Ed Iskendarians camshaft shop and they had plenty of it.

A lot of guys on here, including myself, run 15W-40 diesel oil, which is high in zinc. You can find it in any WalMart or tractor supply store. Personally, I run Rotella in my 261.

The engine and oil are not hot when you start it. That's what multi-viscosity is for.
The factory recco for straight weight oil is 20.
30W is not "weight", it's "winter" (viscosity at 23° F, -5° C): thick all the time.

Panic Almost no one knows what that W means ! Your like me notin texas where its mild--up here in cold country you gotta do something. Have studied that zinc problem, you'd think Walmart would adress that...no zddp at Wally World ! I find the parts stores have it ,so need to learn how to use it. Ive got so if I put in oil (quart) add 2 oz. of zddp ! One FLAPS has zddp in like a ketchup squirter easy to get the 2 oz.I think that might have even been Lucas !