Synthetic oil

[jlerviti]

I have 1951 Chieftain which I'm in the process of getting back on the road. I run synthetic oil in my motorcycle and wonder if it would be a good idea to do the same for the Pontiac. I presume that I would need to drop the pan and clean it thoroughly but after that it would seem to be a better oil for the engine which should help in heat reduction and a longer change cycle. Any thoughts?

[Larry]

I have seen discussions of this in Old Cars Weekly and on-line. I would do a search and see where the opinions lie.

You certainly would need to drop the pan and clean the screens and the entire pick-up assembly in the pan. A total flush of the engine would be good too. However, there will always be the age old question too of whether the car was run most of its life with non-detergent oil. Lots of cleaning, flushing, and switching to a new detergent oil can cause some problems... or so they say.

I have not really experienced anything bad switching to a detergent oil in an older car unless it had hydraulic lifters that then got "too clean" and became noisy. If clearances are so loose that only oil buildup is keeping things tight, then you were ready for a rebuild anyway.

Now, back to the synthetic oil question... Unless you have a good oil filter set up added, there doesn't seem to be any good reason to move to a real long life oil. As far as being a "better" oil, a 1951 engine will be happy with any of the new oils, synthetic or not. Plus, with a vehicle of this type, oil changes should be every 2000 miles or at least begining and end of hobby season regardless of miles logged.

Bottom line... a good name brand 30 weight oil is like honey to an old engine, and it will smile and perform well. If you plan to run during cold weather too, use a 10W30 or 10W40.