[dannymarilyn]

After 3 years and 8000 miles I drained the T6 oil and sent in a sample. Over the coarse of the 3 years I did add 6 quarts new oil. Based upon the spot of oil under the engine I suspect most of the oil consumption was leakage. I did recently find the rubber boot on the drive train for the blower was not tight to specification and there was oil residue there.

I have seen no change in oil pressure or consumption with the T6 compared to straight 40wt DD approved oil.

The results from the oil sample are back and the iron barely increased which suggests very low wear. All other elements and properties were just fine including shear viscosity and TBN. Blackstone said they see no problem with letting the oil run another year, but I had already drained it.

Philosophically, I'm comfortable with analyzing specs, making what I consider conservative decisions while gaining the advantages of new technology, and lab testing rigorously. I don't expect everyone to agree with my approach since there is no approval of this from the manufacturer, but as I noted previously there is no way to test this "new" oil, the test engine died and will never be replaced. However, I do need to pay attention because soon there is a new engine oil classification system being implemented and there is no way of knowing how oils might change as a result, or even which oils will remain on the market. I should also note that if someone chooses to have oil sampled and analyzed as I did with the T6 oil they may find that they too could run 3 years and 8000 miles and still have good oil. I would be surprised if indeed that weren't the case.

So what are the advantages of T6 versus straight weight oil? I have proven that I can go 3 years and 8000 miles between oil changes and still have very good oil. I can buy oil off the shelf at most truck stops which I found not to be the case with straight grade oil and so I used valuable storage space carrying oil. The engine cranks faster when cold which makes for quicker starting. I can have all this without increasing my operating costs compared to annual oil changes with straight grade even if T6 cost more per gallon which it doesn't always.

Take this for what it is worth to you, I make absolutely no guarantees that your experience will match mine. I'm just sharing my experience and what it means to me.

Dear John, How's the oil change working for you? We did had to have United Engines do an inframe overhaul on our 1991 8v92 and now that we are a new starting point, I'm thinking about how to best take care of this rebuilt engine. The #4 cylinder ate one of its exhaust valve seats. After discussion, we decided an overhaul after
32 years was the best course of action. Please advise.