A thought for selecting what oil to use in an antique car. Somewhere, I can not remember where, I read a recommendation that synthetic oil be used in antique vehicles. The idea was that these cars and trucks are seldom driven, resulting in long periods between engine starts. During these long rests conventional oils drain off the interior surfaces of the engine, exposing the metal to air and moisture, and allowing corrosion (rust) to occur. Synthetic oils, the proponent claimed, adhere better to the metal, maintaining a rust preventing layer of oil longer than conventional petroleum based oils. Based on this concept, it would also be expected that synthetic oil would maintain an oil film in the bearings longer, reducing wear during engine start. Based on this concept, in 2017 I started using synthetic oil in my 1927 Ford T. I use the cheapest I can find (Walmart’s house brand) and maintain the same change interval as I did with petroleum based oil – no oil filter on a Model T. I can not say if I have reduced any wear. But I can say that drivability of the T was improved. The Model T has a 2-speed planetary gear transmission, and as such has no true “neutral” as found in a sliding gear transmission. “Neutral” in a Model T transmission is a position in the travel of the clutch pedal between when the clutch has released but the low speed band has not yet tightened, an elusive position Model T enthusiasts refer to as a “Free Neutral”. Synthetic oil seems to produce a thinner, yet more effective, film layer on the low speed drum in the transmission. This thinner oil layer is allowing a more positive release and application of the low speed band, producing a broader zone in the clutch pedal travel where the transmission is in “neutral”. The more positive release and wider zone of release makes “neutral” easier to find and easier to hold (important when waiting on the traffic light they always put at the top of a hill) – hence improved drivability. I must caveat this on that when I was using petroleum oil I was using 10W40 oil. With the switch to synthetic oil I was forced to change to 10W30 oil. I do not know how much of the improvement is due to a lighter viscosity oil. However, the improvement in drivability has been observed over the entire range of engine (and oil) temperature. Cold oil right after start, or hot oil after a long drive, drivability, and finding “Free Neutral”, is equally improved.
Month: January 2019