What kind oil do you recommend for 2007 century w D14?

after 40 years of diesels
I found what ever it has been using continue that
you change oils and viscosity built up sludge can loosen and get clogged elsewhere
that said personally I like straight weight oils 40 in the summer 30 in the winter
old engines always added Lucas
new engines now all synthetic
depending on where you run etc etc

everyone has a different opinion none wrong

 

I agree with Cranky. I've read quite a few of these oil threads and pretty much come away with the same thought every time. It doesn't matter - just go with whatever the manufacturer recommends and stick with it. Perhaps decades ago you could ask this question but nowadays oil is so homogeneous you wouldn't know/recognize the differences and/or effects on engine performance. Mobile Delvac or Rotella T5. You can also spring for synthetic but if you're changing your oil at 12-15k intervals than you're likely just wasting money. The main advantage of synthetics is that they allow for a larger change interval, but most truckers I know get uncomfortable running that long between changes.

 

run the slick kind, hell long as its 15/30 SAE30/SAE40 whatever mfr says to use use it. buy it by the 55 gal drum esp if you doin it yourself much cheaper.
i was looking and 55 gal drum of oil was 400.00