Misunderstanding on synthetic oil's origin is understandable when one remembers that the early WW II synthetic oil was just that... a man made lubricant based on vegetable oil.... and it was a necessity due to regular oil shortages.

Agriculture Canada was one of the key player in designing/discovering a very high performance vegetable oil for high output engines in particular torpedo engines.

The oil was based on the "rape seed" which later became socially unacceptable and was renamed "Canola oil".....CANadaOilLow Acidity...... and now it is sold as a low cholesterol oil for French Fries.

So next time you eat Fries and fell like going like a torpedo you will know why...

The later "synthetic" oil was created in labs from petroleum based oil particularly for the oil hungry jet engines.... and later used for gas engines in extreme cold conditions in Alaska.

Synthetic oil has a lot of advantages but on old totally rebuilt 235/261 good old fashion HD Diesel oil like Rotella is probably best for the solid lifters and looser tolerances....

Rotters in Ottawa have migrated to HD Diesel oil and now add Zinc additives for safety.

That being said I have driven 100s thou miles on two Ford Diesel with 0-40 synthetic and it makes one H**l of a difference on cold morning when it dips to minus 30 F..... yet the same oil performs well after 8 hours at 75mph on the 4 lane highways. At 4 gallons per oil chages it is costly...but so is repairing the diesel.

And I still buy and use straight 30 non-detergent in my single cylinder make&brake engines... thats' what they were designed for..... sludge is welcomed as it seals the oil leaks...!!!

Bob C.
Ottawa


Bob C.
CMP Heaven
The Hammond Barn