Packard Forum Index » General

After a recent conversation with a fellow who runs a engine rebuilding shop, I decided to switch from SAE 15W-40 oil with zinc additive to Joe Gibbs Driven Racing SAE 15W-50 oil. This racing car developed oil is loaded with zinc and is a conventional oil, i.e. not synthetic. He assured me that there would be no discrernable difference between the 15W-40 that I currently use in my Clipper and the 15W-50 oil.

My question is this: Have any of you out there switched to this kind of racing oil and what were the results? I have to tell you that this racing oil is expensive -- about $9 a quart. But I have had a tough time trying to find 15W-40 oil anywhere and the only one I can consistently find is designed for diesel engines.

I run 15w-50 racing oil in my 35 Cadillac just because of the zinc. The only drawback for me is that my caddi don't have a dipstick but a floating rod with an indicator in top and because of the heavy oil the float is not very responsive. Haven't changed oil yet in my 36 Packard but I think I will use the same oil.

SAE 15-40 is an oil for both gasoline and light diesel engines and widely available and used in the hobby. The whole "zinc thing" is pretty much irrelevant to Packard engines as they all have quite low valve spring loadings. If your 36 Packard is a senior it has roller cam followers and the zinc additive is even more irrelevant. Just use a good name-brand oil and change it at least annually.

Owen and BDC:

My car is a 1955 Clipper Constellation with a 352 cid V-8. I've been told by both the previous owner and by several members of local Packard clubs that this engine definitely requires zinc in the oil. I change my oil twice a year and at the same time service the Twin Ultramatic, which generally operates OK.

Lubriplate has zddp?

Comes in multi grades

Hey O_D is back!

My 36 is a junior

According to Wikipedia:

"The main use of Zinc dialkyldithiophosphates (ZDDP) is in anti-wear additives to lubricants such as greases, gear oils, and motor oils, which often contain less than 1% of this additive. It has been reported that zinc and phosphorus emissions may damage catalytic converters and standard formulations of lubricating oils for gasoline engines now have reduced amounts of the additive, though diesel engine oils remain at higher levels.[3] Crankcase oils with reduced ZDDP have been cited as causing damage to, or failure of, classic/collector car flat tappet camshafts and lifters which undergo very high boundary layer pressures and/or shear forces at their contact faces, and in other regions such as big-end/main bearings, and piston rings and pins. Roller camshafts are more commonly used to reduce camshaft lobe friction in modern engines. There are additives, such as STP(R) Oil Treatment, and some racing oils such as PurOl, Brad Penn and Valvoline VR-1, which are available in the retail market with the necessary amount of ZDDP for engines using increased valve spring pressures. The same ZDDP compounds serve also as corrosion inhibitors and antioxidants."

There are several clear differences between what went into cars 50 years ago and today. Gas in 1963 contained lead, which diminishes pinging and allowed for higher compression, as well as lubricated valve seats. Cars ran at 97 octane premium, compared to 93 octaine today and gas did not contain ethanol, which as far as I can tell, does not improve performance, gas mileage, or reduce polution. I do know for a fact that ethanol, especially during colder winter months, radically affected my Clipper's performance.

Cars in 1963 also used straight motor oil, not the synthetic oil currently found in most newer cars.

Mr B,

If you are talking about the Kendall Super D-3 15-40, it is a very high quality oil. I have used it for over 30 yrs, it keeps the innards clean as a whistle. Put 366,300 miles on 93 Chev 2.8 V6 and still had great oil pressure, no smoke, no metal in pan until it was laid to rest in 2009. My brother who is head mechanic at a NYS park regional garage runs it in every piece of equipment he has charge of from trucks to park police cars.

I would highly recommend the Super D3. What I am planning on running in mine when I get the engine apart and back together.

My current system is "total loss", no changing required, just add a quart every 75 miles!

Ok, so not ideal, no expensive oil for me until I find and repair my leak!

My experience (not with Packards) is that good ol' Rotella 15-40T is an exceptionally great oil for both diesel and gas motors.

Rich