Oil for the Model T - the smoking gun

[dykker5502]

Apologies if proof for what SAE quality was intended by Ford back in the the day have been brought here before - given that SAE system for specifying was first established in the early 1930's (as far as I have been able to Google), but I hve just found what I will call a smoking gun! A booklet from the time that maps between the classical specifications of Light, Medium , Heavy etc and SAE.

Fords specification was "a light oil" what ever that was, and that have been discussed for decades.

In Denmark a oilcompany was established already in 1899 - The Danish Petroleum Company - abreviated D.D.P.A and it represented PRATT oils in the 1920's and 30's which later became Standard Oil at some point and sold ESSO gasoline and lubricant. In 1986 it was taken over by the Norwegian oilcompany Statoil, so the company somewhat still exists.

Anyway - in the early 1930's it published a booklet titled "Know you car" ("Kend din vogn"):

The booklet brings you through all parts of your car and how it work, and the last part of the booklet is a table showing what oil you need for your car (or motorcycle):

The top of this page holds a list of STANDARD oiltype and it is "translated" to the brand new - TADAAAAAAA - S.A.E visocity classification system!

So now it is just about to find Ford Model T and that is on the next page:

SO! Ford Model T should have STANDARD Motor oil Medium = SAE 20 (and Model A Standard Motor Oil Heavy = SAE 30)!!

And that is actually compliant with my experiences that the engine have fewer "noises" when running on SAE 20 than 30, and the explanation is simple: Model T have splash lubridation and the thinner the oil the easier it comes into the bearings, which originally was intended to come from the sides and into the middle of the bearing.

OK - Now let the party begin!

[Adam]

And those are the recommendations of an oil supplier sometime in the 1930’s by the looks of it...

All of “today’s” oils didn’t exist then. Things change...

[DanTreace]

Michael

Here is another chart..... 1930.....also.

Has the Ford T using 20w in winter, and 30w in summer, with 40w for high speed summer heat.

Since today's oils are nice with multi-viscosity, for me....10w-30w has worked with my FL climate.

[Kerry]

I don't think that the lighter oil was a splash lube consideration for the T back then, after all most engines of the day had splash lube, it was as it is today, all about having the clutch operate correctly.

[John kuehn]

Today’s store brand oil from WalMart, Auto-Zone , the dollar store and etc is a vast improvement from what was available in the 20’s and 30’s. 10w-30 works fine in Texas.

[dykker5502]

Today’s store brand oil from WalMart, Auto-Zone , the dollar store and etc is a vast improvement from what was available in the 20’s and 30’s. 10w-30 works fine in Texas.

10w-30 is basicly a SAE 10 oil with additives that make it act as a SAE 30 oil at 100 C, so kold it's even thinner than the monograde SAE 20. The modern oil just has better formulation and further additives that make the thin oil have better ability to bear the strain in the bearings.