Re: what kind of oil do I use in a 1951 Packard 300

Posted by Tim Cole On 2009/5/8 20:29:23

Hi Roger:

Pulling and cleaning the oil pan is sound advice and also is part of Packard scheduled maintenance. Once a year in 1948 (I don't have a '51 manual handy).

If the motor is heavily sludged then detergent motor oil will simply use up all the additives real fast and become like dirty oil. However, good non-detergent motor oils are hard to find. Castrol has a full line of ND for which they claim is state of the art sans detergent, but I'll be darned if I can get a hold of it. Most other ND is just not very suitable for Packard motors unless is it changed every 500 miles.

Packard didn't like heavy motor oils because they run hotter and strain the oil pump. Single grade detergent motor oils are generally recommended as being heavy duty and intended for severe usage like trailering.
Again Castrol has a full line of these that may be available through NAPA.

The heaviest I would run is 10w-30 although I would prefer what the book says 20w. These multi-grades can run heavier or thinner base stocks.

The most important thing here is to change the oil regularly as the manual says and avoid short period running.

I'm not sold on these heavy multi-grade oils because this zinc stuff is directly opposed to what the petroleum engineers say about SM rated oils. I think these problems are likely the result of neglected oil changes and dirty oil pans.

Good luck.