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Car didn't have oil filter canister when I got it. I used 30W conventional (no additives) at first. Next I used 30W Valvoline VR1. Local classic car shop recommended 10W-30 so I bought Lucas 10W-30 Hot Rod oil. Haven't put it in yet. I think many here would suggest 30W but is that for an original engine? What about an old rebuild engine?

My rebuilt 282 has Mobil 1 5w30 synthetic in it. The engine doesn't seem to mind.

Not actual advice, but I thought 15W40 seemed to be the most popular choice?

Packard specified 20 weight oil, so 10w-30 should be fine. I assume they recommended racing oil because of the higher zinc content. Risolone offers an additive which might be cheaper than racing oil if you want the high zinc. Heavy oils serve mostly to rob horsepower via taxing the oil pump. I don't know if the valve springs in a 70 year old Packard are strong enough to benefit from the zinc.

My lawnmower specifies 30w oil and I buy the B&S oil only because the engine doesn't have a liner and I haven't checked what is in the stuff.

I do recommend dropping the oil pan because oil filters were an option. Or you can buy a borescope from Harbor Freight and inspect it that way via the oil fill hole.

Tim's on it.
Do you mean it has a oil filter canister now but not when you obtained it or when rebuilt?
If yes, much ado about nothing, unless it's a partial and badly sludged up in there.
If you're running the BAJA or circle track with it, or driving it once a month around town in nice weather, different lube oil services.
We seem to take advice from sale people who's job it is to sell us up. Hey, what's an extra buck or two for old betsy?
They didn't have detergent and viscosity additives that's why it was classified straight grade. Viscosity measurement was in it's infancy in those days.
If one looks at the viscosity curves w. Temperature, not that big a difference between 20 and 50. But higher affects flow and pressure requirements. Worse is cold flow to the oil pump. Starves the motor of lube until it warms up.
No way to tell what parts they used long ago in the rebuild. Lots of material changes over the years require different lube specifications.

It has a oil filter canister now but not when rebuilt.

I drive it every day. I've driven it 530 miles since I got it back from the transmission shop on 18 July.

No sales person has been involved in the oil selection discussions. I am inclined to follow the advise from the local "old school" engine mechanics in the shop that specializes in classic and antique cars. That's where I got the 10W30 from.


I just now found out that the machine shop that rebuilt the motor is still in business but at another local location. I'll see them tomorrow.

Packard indeed recommended SAE 20 in warm weather.

SAE 10w-30 is thinner at 32*F than SAE 20, and thicker at 212*F than SAE 20.

In other words: SAE 10w-30 protects your engine better in both hot and cold than SAE 20.

It's not just for winter use, either. SAE 10w-30 is the same as SAE 20 at around 100*F. It's thinner below that, and thicker above it. That means 10w-30 will flow quicker when you start your engine on a 70*F Sunday morning.

That lawnmower oil I mention is rated SJ which is the higher zinc content. After SJ zinc was being reduced, so there is an example of a manufacturer wanting the zinc.

Thus, given how expensive those motors are leaning toward original specifications is meritorious.

As mentioned, Risolone sells a zinc additive for oils rated higher than SJ. At present those diesel oils have higher zinc, but the lighter grades sometimes are hard to find in stock.