Synthetic oil

[Booger]

I been thinking about this for years and I just searched the archives for some feedback but in the end Ima gonna throw this out here. Ive always used dinosaur oil in my old cars Why?

In the 40s and 50s they all left the factory like that. The tolerances and metals were just that way. But now theres so many advances with the semi and synthetic oils.

Booger doesnt get out much. Should I change over? Your thoughts...

[desoto1939]

Booger: My first question that I am going to ask, Has the engine been rebuilt and I mean a total rebuild recently?

 

Does the car have a By-Pass filter or the metal oil car filter?

 

What weight oil have you been using in the car since you have owned it?

 

How many miles on the car and engine?

 

How many miles do you put on the car every year.

 

Is the car kept in a heated or unheated garage.

 

Basically if the car is still original then I would just stay with the old style 5-30 or 30 straight weight oil.  The modern oil is so much better then the original oil but going to a synthic blend of full synthtic you might have issues with sludge and the various gaskets might also start to leak.

 

Also what type of anti freeze do you use.  It is recommend that you use INT style which is the original Green AF and not the newer universal extended life AF.

 

Rich Hartung

Desoto1939@aol.com

[Booger]

all good points Rich My guess its been rebuilt It has and orange block

It has a external filter I now use the sealed disposable canister as I am over the leaky cans

Its my belief it has 85k miles

booger treks only 1000k miles a year and does do freeway speed (62 mph)

my garage is insulated but unheated

going back to the 60s Ive always used 10w 30

and I use the original green AF

dropped the pan 2 years ago and cleaned minimal gunk

[desoto1939]

Booger if the engine is running fine and there are no leaks and any issues I came from the theory that if it is running and not broke then do not fool with anything.  The engine has treated you well so why tempt a change. So long as you can still get the 10W30 oil then you are good to go in my estimation.

 

Rich Hartung

[keithb7]

Personally I would not run synthetic oil in these old engines. If you do I suspect the engine will burn and leak a lot more oil than it does today.

 

For my clean, rebuilt engine,  detergent dino oil is just fine. No zinc added.  

[Sam Buchanan]

Walmart, Autozone, etc, the least expensive store-brand detergent 10W-30 oil on the shelf......the P15 is happy. That oil is far superior to anything available in 1948. 

Edited December 19, 2023 by Sam Buchanan

[Booger]

the 3 wise men at Christmas time. I might have known. Why do I keep hearing a little voice in my ear saying if it was broken in on conv oil thats what you stay with.

Thank you all and have a Merry Xmas

[FarmerJon]

I drive my p15 a fair bit, and change the oil spring and fall, that still works out to less than 3000 mi per change, maybe closer to 2k. The extra cost of synthetic isnt worth it for me. 

That said, i have noticed that most of the aforementioned cheapest Walmart and parts store oil is "semi synthetic" or "Synthetic blend" so it may get to the point before long where "good ol' dino oil" is the more expensive option.

[Doug&Deb]

While I agree that any cheap oil is superior to what was available back in the day I still prefer to use a good quality oil. That said I ran non detergent 30W in my Coronet until the engine rebuild. 

[capt den]

synthetic oil just burned thru my engine a little faster than the old conventional oil. the manual for my car [54 windsor] calls for oil changes at 5000 miles. i do it more often. the old filter is a mess to change and the filters have gotten costly. chrysler did not even put a drain plug on the cannister. why the heck not? i use 10w 30.    capt den

[Dartgame]

I have been looking at zinc (ZDDP) levels in conventional motor oils and found several brands are making them for use with flat tappet engines like ours and most older v8s. Valvoline VR1 - 10w30, 20w50, 30 weight etc. seems to be readily available and contains what appears to be the correct ZDDP level. Pricing is around 35-40$ for 6 quarts. I figure why not use it, how many times do you change your oil ? Its probably not critical to have the "right" amount of ZDDP with a flat head due to the low valve spring pressures these engines use, but what the heck.