In 1998, when Marda and I wrote the specs for a new Volvo tractor with a Detroit 60 engine, I specified synthetic oil everywhere except the engine.
After the first 15,000 miles -- that is, at the proper time for the first oil change -- after the internal parts of the engine had pretty well worn together -- then I changed to Delvac 1 (the Mobil synthetic product for heavy-duty engines).
My intent was to continue with Delvac 1.
Theoretically, that approach appealed to me.
I thought it was right.
I still think so -- provided that no uninformed, insensitive, uncaring, numbskull, bozo screwball grease monkey -- or service manager -- screws up the program.
Unfortunately, though, two major incidents -- along with several smaller ones -- changed my mind.
At the Petro in Casa Grande, during a routine(!) oil change, after I asked for Delvac 1, the guys in the pit drained the crankcase.
Then the shift manager approached me very sheepishly and apologetically.
He said -- with much embarrassment -- that he had no Delvac 1.
Immediately, though, he voluntarily offered to give me a fill of regular Delvac oil -- and new filters -- with absolutely no charge whatever to me -- not even for the filters.
I graciously accepted his offer, and we parted on friendly terms.
Later I changed back to Delvac 1.
Two years later, at the Freightshaker dealership in Amarillo, when an urgent repair required a refilling of the crankcase, I repeatedly emphasized the need for topping off with Delvac 1, and I specifically referred to it as the Delvac synthetic oil.
The functionaries at the desk said that they would take care of it.
When I paid the bill, I saw that the price for the oil did not correspond to Delvac 1 but rather to regular Delvac.
The remainder of that conversation then quickly began to resemble a comedy routine by Abbott and Costello.
When I asked about Delvac 1, the response was "Whaddayamean?" or other likewise inspired and enlightened words to that same effect.
Even the service manager, to whom I quickly took the problem, claimed not to know about synthetic oil or to understand the differences between fossil oil and synthetic oil.
How can it be that in 2000 the service manager at a Freightshaker dealership did not know about that?
Anyway, in disgust, I then gave up and went back to regular Delvac oil in both our trucks.
Since then I've again stuck with regular Delvac.
To me, Delvac 1 is not worth the trouble or the expense.
To keep the engine warranty in force, I needed to use only extreme-service oil filters and to change them mid-term (and get an oil analysis) at 30,000 miles (with oil changes at 60,000 miles).
The manual for the engine in our new truck calls for oil-change intervals of 25,000 miles -- even with regular fossil oil.
Our new truck has synthetic oil everywhere except the engine.
I intend to keep it that way -- with regular Delvac oil in the engine.
Maybe I would get a different result in 2006.
But I feel no need to change from regular Delvac oil in the engine -- especially with the 25,000-mile intervals with fossil oil.
I do not seek to persuade anyone else to adopt my views.
I just report what happened to me, and what I've done about it.
As always, best wishes to all,
Doc.