Originally Posted by EddieCairns
At what time did the oil technology improve to allow it to be used year round.
The very first 10w30 multi-viscosity oils were introduced in the U.S. in 1953 (Amailie, Kendall, Phillips oil). Prior to that, engine makers said to put in 10% kerosene in the winter to thin a straight grade.
I had thought people used very thick oil back in the 1920's thru 1960-ish. I think I was mostly wrong. Owner's Manuals were in the SAE 20 to 30 viscosity range for many years. Sure, people who had hot rods often knew to put in a 40 or 50 weight, due to cam lobe forces and how the greater torque and RPM would stress out crank bearings, etc.
Also, recently I found out that, in WWII, when U.S. Packard was making Merlin engines for P-51 fighters, they said to use SAE 50 for that high powered engine.
From a recent post.
Originally Posted by oil_film_movies
Originally Posted by K20FA5
Remember not all that long ago when the manufactures started specing 5W-30 and everyone said that was too thin?
Guessing people just freak out over the "5w" part because they don't understand its just a cold temperature rating. ... I heard an autoparts counter guy complain that German Castrol 0w30 was "like water" because of the "0w" rating (year: 2003), just silly.
Wonder what people have done with SAE viscosity grades over many years? If we go back further in time,
1980: 10w30 or Xw40: mobiloil.com goes as far back as 1980 on oil recommendations.
1978: the new Mobil 1 5w-20 was introduced
1957: SAE 20 or 30 ...
http://www.oldcarmanualproject.com/manuals/Chevy/1957/Owners/pages/25_jpg.htm
1950: SAE 20 ...
http://chevy.oldcarmanualproject.com/chevyowner/50om22.htm
1940: SAE 20 ...
http://chevy.oldcarmanualproject.com/chevyowner/40om44.htm
1934: SAE 30 ...
http://chevy.oldcarmanualproject.com/chevyowner/34om52.htm
.. and ZDDP wasn't there for most of the oils during the early time. It wasn't invented until 1941, and the industry got used to it years later, when they "discovered" it reduced wear greatly, in the 1950's.
At some point, if you ran a hot cam, stiff springs, you ran a 50 or 60 weight.
Yet most normal driving it was 20 or 30 weight for many years.
From 1934: