re: Calling 6.7 Cummins owners

The higher pressure is one thing and part of it is also the fuel. Ultra-low sulfur doesn't offer quite the same lubricity the old stuff does. It's supposed to have additives that are supposed to help lubricity but they are mostly detergent additives and that is their primary function. Extreme pressure, tight critical tolerances, and reliance on very specific fluid properties and maintenance schedules means very little room for error.