I pulled the very first oil sample on the 2015 EcoDiesel. I was very happy with the results. There's only 5,368 miles on the engine oil, but the oil spent 8 months in the engine. That's a lot of idle time, cold starts, daily short commutes, and some towing. The T6 lost approximately 50% of its TBN capacity as it dropped from 10.6 to 4.91, which isn't a surprise. T6 uses a softer base oil which doesn't hold up to oxidation like a better-quality oil, but it still protected the engine for this type of interval.