sidney wrote:
As the filter clogs... isn't it causing increased flow and increased pressure on the unclogged portions of filter element... leading to a potential filter element tear and failure?
In extreme cases with a paper particulate filter yes. These trucks do not have these types of filters.
They have a coalescer filter on them. Particulate filters are pretty much 2 dimensional and trap contamination only on the surface. Coalescer filter are 3 dimensional micro fiber so they can hold two, three times as much or more and trap contamination throughout the whole filter.
In short, the coalescer filters can hold a lot of stuff with no pressure drop.
Do the new engines measure the pressure drop across the filter? I suspect so, and that would be why they know exactly when to change it. But don't know for sure. Even the old ones measured the rail pressure so it wouldn't take much to measure pressure drop across the filter so the puter knows when it's time to change the filter. :)