Tier 4 Emmisions?

[RumT]

In the whole 3.2 hours (for a total of 5.1 on the clock) I've put on my '14 B2620, I've noticed the engine idles at 1000, or a bit more, and limits at 3000 rpm, per the specs on this specific engine.

In the previous versions of the D1105, idle range was 850-950 and max speed governing was set at multiple speeds above 3k, depending on which sub model.

Any thoughts as to why this is?

A higher idle speed for more air intake and cleaner emmisions?

A lower max speed in order to limit emmisions output?

Thoughts.......

 

[fluxed]

With only a piston bowl change and a minimal change to the three vortex system, higher idle rpm may have been needed to meet tier 4 and drop the particulates by 50%.

 

[RumT]

Excellent point