While we are on the discussion of diesel lube oils, I strongly reccommend Chevron Delo 400 15-40 for most all diesel applications (except Detroit Diesel 2 stroke engines, then you use Delo 100 series).  This is the oil our whole fishing fleet back at home uses this oil, and we have no problems with it.  There are many engines that use this stuff and go 20,000 hours (and more) between rebuilds running this stuff, and these engines range in size from little .9 L single cyl. engines to 1200+HP 38L V-12's.  My dad has run this stuff in his '84 GL since we got it in '85 w/ 5k miles on it.  That engine lasted 155k miles before we replaced it due to bad compression (it still ran strong, just blew oil out the rear crank seal if we were climbing a long grade and lugging the engine).....Another plus is that you can buy this stuff by the quart, gallon, or barell, and it is not all that expensive.  I have a question, have any of you guys out there had oil samples taken and submitted them to an analysis lab?  This is another common practice in our fleet, and it actually can detect an engine failure coming up because the lab can detect small amounts of fuel, metal, and coolant (head gaskets....) in the oil, before we could even see a change in any thing, sorta like a peek into the future....

For what its worth....

-Aaron McKay
'85 GL "Darle"
Student in Mechanical Engineering at
Oregon Inst. of Technology

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