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Message: [QUOTE="TARM, post: 346801, member: 578"] Kingrancher, Blackstone is giving you some bad recommendations IMO. I can not believe they are telling you to go extend your OCI to 12K with oil like that. One, you are 2x the average fuel contamination/dilution which is bad for a number of reasons. Second, as 97F250PSD pointed out, your TBN has nosedived. Not that Rot is high to begin with. It starts at 10.6 on average for T6 and you have lost basically 2/3 of the TBN. On a general use that is the max limit and for people that care about longevity, which IMO is anyone willing to get UOAs, you want to stay in the 40% range as the max. Once you have used 60% of the TBN you need to be not going farther. The % lose of TBN in a number of ways is more a indicator than the actual total TBN numbers. In other words I would rather see a oil with maybe a lower beginning TBN drop a small amount than a oil that has a really high TBN but then drops way down even if that final TBN was still a bit higher than the other oil with a lower starting and final number but with a much small total drop. Total TBN is still important for a number of reasons but the drop % is telling you whats really going on. Third, you have the viscosity which is indicated in this report by your cST 100C value. The shearing is bad which is a issue you tend to see with Rot T6. Your oil has dropped somewhere between 2-2.8 SAE levels or a loss of 20. It started at a SAE 40 (5w40) and you are now a mid SAE 20 That is too thin oil IMO for our injectors and engine. A single SAE drop is fine but once it gets close to hitting the bottom end of that level its time for action. If its a high quality REAL syn oil and certain other things are still well inline then the addition of certain additives can be used to restore the lost vis from shearing but this is not the case with Rot. IMO the reason I think Rot T6 seems to shear much more than other Syn: They use cheap base oils and then get the viscosity thru using large amounts of viscosity modifier additives. These get used up very quickly thru shearing. The viscosity from high quality base oils is much more stable and shear resistant compared to the additives. I also think this is why you see these oils tend to drop 1/2 to 1 SAE level and then you will see the shearing rate drop way down. The first drop is the additives and then when it slows you are into the base oil stability. One thing I noticed on your UOA is that you report no oil addition at all for 10,000 miles. Is this correct, you have not burned any oil at all in 10K miles or more correctly have not added any oil to the crank case as the two are not exactly the same thing? I would expect to see somewhere between 1-3 quarts used in the average 7.3 in 10K Homesteader, I think if I read it correctly its the Scaheffer's EP Moly Additive #132. This stuff is great stuff. I use it for install lube on engine parts as well as to combat shearing and other loses from extended OCI when I run my bypass filter(Luber Finer 4 quart). I am seeing how well these HE Donaldson Endurance full flow filters work. The one I am running holds an extra quart of oil over the stock filter and has a 15 mic absolute rating which is about 50% better than standard full flow filters which are around 30-35mic. [/QUOTE]