With the ever increasing competition in the diesel market three seems to be no end in raising the HP on the Cummins. What is a realistic limit for this 5.9 liter engine and still maintain 400,000 mile reliability? I'm sure a lot of you have been running your trucks "bombed" with 400 or more BHP for many miles. I guess you guys would know best. Anyone run 400 hp(flywheel HP) for over 200,000 miles with no major mechanical (rods, pistons, head gaskets, etc.) problems?

 

Lots of them fail b4 100,000 unbombed...just depends..on the integrety of the guys that that put it togather in the 1st place.
If you dont belive this go for a drive and interview a few shops. Dont ask cummins cause they will not know anything about it ,as they are out of the loop.
t.m.o.