Re: New available motor oil

Posted by 55PackardGuy On 2014/7/23 11:09:16

Detergent or non-detergent, that is the question.

Whether 'tis nobler to go easy on the engine crud,

or to flush it out.

I know not whence, but I can say that many, many cars were built before the days of detergent oil. I believe, nay, am certain, that detergent oils were available in the '50s. I also will offer the observation that small aircraft piston engines used non-detergents. Their dipsticks were immaculate.

Detergents do just what you'd expect a detergent to do... clean things up. Some folks say that's a good thing, some folks say no. I believe the small aircraft spec for non-detergent oil was to eliminate any chance of a clogged line. Often, these engines were flat opposed, air-cooled "Volkswagen style" engines (NOT made by Volkswagen). BTW, on the topic of Volkswagen, the old bugs did not have oil filters. Neither did many older American cars. Then, they became an option. They were either "bypass" which kept oil running through in case of a clogged filter, but didn't filter all the oil every time through the engine.

The postwar Dodge flathead came with a bypass filter, but you could order a full flow filter as an option.

The '54 Packard 327 in a Clipper Deluxe had no filter as standard, but you could buy a bypass filter as an option.

Of course, as you V8 guys know, the '55 offered a bypass filter only.

I know the screen on my oil pickup is clean enough, because my pressure comes up right away and the oil light goes out. But it probably isn't perfectly clean, hence my detergent oil + Marvel Mystery Oil experiment.