Packard Forum Index » Post-War (1946-54)

Question: What oil should I use in my 1950 Packard?
Should I use a detergent or non-detergent oil?
Recommend a brand and weight! Thanks; JE

As long as you have an oil filter, you should use detergent oil. If you don't have an oil filter you should get one. Detergent oil can drastically reduce or eliminate the formation of sludge.

SAE 10W-30 is ideal for all post-war models in any climate where temperatures never fall lower than -10 degrees F, assuming the engine is in decent shape.

The general consensus is that most motor oils these days (API SN) have too little ZDDP (an anti-wear compound). The quick way around this is to use a motor oil designated for diesel engines, but make sure it also has a spark rating, I.e it also meets the standards for gasoline engine use. API SM or SL is usually what these oils carry. Chevron Delo 400 LE 10W-30 has 1200 ppm zinc, can be used in gasoline engines, and can usually be found easily. Other options include Mobil Delvac and Shell Rotella T triple protection.

Costco sometimes stocks Chevron or Shell, though I've only seen them carry the most common diesel viscosity, 15W-40, which is more appropriate once you've got higher amounts of wear in your engine or are regularly running your engine hot. 15W-40 is too thick to adequately lubricate until the engine is at operating temperature.

Your engine was designed to run with straight SAE 30 in the summer with lighter oils being spec'd for winter as a compromise to make sure the engine would still crank in cold weather. When multi-viscosity oils came out in the mid 50's Studebaker Packard updated their recommendations to recommend 10W-30 for most conditions, as did Shell when they issued their lube charts.

"you should use detergent oil"

I'd think that should have a caveat attached of only if the engine has been recently cleaned of sludge. If there's a sludge build up in an engine detergent oil could loosen it and create a problem by blocking the oil pickup causing oil starvation. If I remember rightly, this happened to another poster here recently?

Quote:

Ozstatman is correct. If the engine has been running non-detergent oil (if the oil you've just drained from the pan is non-detergent oil) you will need to inspect and clean sludge if present.

The assumption underlying my recomendation is that since detergent oil came out 50+ years ago, the pan has probably been off more than once and the engine has probably been running on detergent oil most of its life.

But that's a big assumption, as Ozstatman points out.

Perhaps a better way to phrase it would be, "if you've been running non-detergent oil, don't switch without cleaning out the sludge. If you've been running detergent oil, keep using it."