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I read in the 1954 Service manual that the recommended oil for the 327ci Straight 8 Thunderbolt is 20W SAE in most driving conditions but I was wondering if it would be better to use s synthetic mix so that you get the best of both oils? Also - what would be the best fuel? What octane? With or without ethanol? Thanks

Frank, I have used synthetic motor oils espcially Mobil 1 in my daily drivers and more modern collector cars for many years but for my 1947 Packard I use a 15/40 Diesel oil , usually Shell Rotella but any brand will do. I suppose that a 100% synthetic or blended would not hurt but probably a waste of money as I don't really see a benefit in the types of driving and speeds we typically use our Packards. Others with equally valid reasons may have a different opinion.
Eighty-seven octane is all the octane your engine can use and if you can get it without ethanol so much the better but if not don't worry about it. There have been other postings on the subject so if you do a search you will find other opinions on these much discussed topics.
for example;
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=2035&forum=1&post_id=19442#forumpost19442

And BTW if you haven't already done so please post a photo of your Packard in the Packard Owners Registry before a certain Aussie sends you a reminder!

My mechanic in my home town who I have been going to for over 25 years stated the following about using synthetic oil. If you change your oil between three to four thousand miles on a regular basis, using synthetic is a waste of money.

I would like to here other person's thoughts on this in another thread.


John F. Shireman

Quote:
Dave,

The photo is in the Owner Registry, it just doesn't display until you open up the Registry entry. Probably too big a size file, but the more computer literate can advise on that.

Signed "a certain Aussie"

.....using synthetic is a waste of money.

John, many of us drive our Packards less than 1000 miles a year with many cold starts and shorter trips. Best practice for this type of use is to change the oil annually regardless of whether you've got a few more or a few less miles than that. So if you do that, you're wasting a primary benefit of synthetic oil which is prolonged oil change intervals, thus for those circumstances I agree with what your mechanic said.

I also think for those of us that experience a winter season where the cars are idle, the best oil change time is when the cars are laid up, thus they winter with fresh oil free of condensation, acids, etc. that accumulated during the driving season.

I'll just add my support to the prior recommendation on gasoline; with the exception of the 1954 359 motor and the 374 V8s, anything over 87 octane is not required and offers no benefit.

PS - and if the original poster can tell us where to buy fuel without ethanol (other than an airport) I'd like to know.

Thank You All for the information. I'm not sure why the picture of the car is not where it should be. I have registered and intend to add more pictures when I get a chance.

Short answer: 10W30 and regular gas.

Long answer: Multigrade oils were new on the market when your car was made but all car makers recommended them as soon as they were available. 10W30 will be right for your car in any driving conditions you are likely to see. You might want lighter oil for below zero or heavier oil for above 100 degrees but I doubt you drive your Packard in such conditions.

Today some experts recommend using 15W40 Diesel oil because they have cheaped out on the high pressure additives in the gas engine oil. This is to reduce pollution on oil burning engines. Today's OHC engines do not need the high pressure additives like the old pushrod OHV engines did. In your case you have a flathead which is even easier on the valve mechanism than an OHC so you have nothing to worry about.

On the gas question, whatever engine you have, the octane should look like the compression ratio.Your engine with 8:1 compression would love 80 octane gas. Naturally this is not an exact rule, 87 octane regular will be perfect. There is no advantage to using hi test, quite the opposite. A low compression engine will run better on low octane gas. It will start easier, run smoother and cooler and develop more power and mileage on low octane.

Rule of thumb on octane, take compression ratio, multiply by 10, and this is the octane requirement. Diesels are excluded in this formulae.

Owen: I guess that I should have stated that I asked my local mechanic about using synthetic oil in both my Buick and Ford Ranger. He stated to me that as long as I changed my oil at regular periods, which for me is between three and four thousand miles, that he could see no advantage to using synthetic oil. That the to him he thought it would be a waste of money.

Myself I see no advantage in using synthetic oil. My Ford Ranger using Valvolne Oil with 130,000 miles consumes no oil in between changes and still runs strong.


John F. Shireman

I am not sure there is enough zinc or phosporus in modern oils.This is why people go to the diesel oil. They have more Z and PH. I do know the first thing you MUST do is drop the oil pan and get the 1/4 inch of old sludge out of the pan and any where else you find it.If you dont...That nice new oil will clean out your engine and run it thru your motor."Not" good get as much as you can out first.From what I understand.(Minimal possibly at worst.)Is there is more metal to metal contact in older engines.The old additives are needed. Brian