As stated above, Rotella also offers their T-Syn 5W-40 Synthetic diesel oil. It can be picked up at your local Wally World for around $20.00 a gallon.

The attached PDF Oil Comparison Chart was put out around 2007.5, but it has some very useful info in it. The first couple pages just explain the criteria for the test. Pages 3-4 show the charts of what oils were tested and where they ended up in the ranking. All oils were tested "blindly", with the testing crew not knowing which oils they were analyzing untill all testing was completed. It's an informative read if anything.

 

i used rotella at work in every machine i have. over the past few months, prices going up and chit, i switched to a different company for cheaper oil. now i am running kendal super XDA titanium 15w40 oil. was 400 buck cheaper at 250 gallons then rotella.
http://www.conocophillipslubricants....0TDS%20Web.pdf

 

I would be careful changing a truck that age over to the CJ-4 oil, try to find the CI rated.

 

what truck? my 6.9? it just likes having any oil in her

 

I have used rotella in many of my vehicles, from Hyundais to Mack trucks, never had any problems.

 

I have used Mobil Delvac, Rotella, Delo, Royal Purple, and Castrol in my 2002 24v. Delo seemed to be the best, insofar as running quieter, smoother, and not smoking on startup. Royal Purple was the worst, with the Castrol being only a hair better. I called Royal Purple (they are located 10 minutes from my house) and they said that you should still change it at the recommended intervals listed by your vehicle manufacturer. Couple that with a blue haze in the morning after initial start...I ditched it at the next change. Rotella made just a teensy bit of rattle/tick noise while cruising, but I have no idea what parts were making the noise or how oil could affect that. I am currently running the Mobil Delvac because O'Reilly had a buy-one-get-one sale, but Delo will be getting my business next time around.