Posting this up for a friend. '03 F250 7.3L with 122k miles. Truck is used in his Landscaping Business with short trips and towing(3-5k lbs) 75% of the time. All the UOA's have been with Schaeffer's 9000 5W-40. Its surprising to see how all the metals dropped this OCI, he hasnt changed anything. Running/Towing the truck the same with Diesel-Kleen every few tanks. Might be towing less due to the cooler weather though. Switching to Rotella 15W-40, the Schaeffer's was getting a little expensive.

Cool! He could have gone longer on the OCI. What about Rotella 5W40?

Make up oil is way too much for only 3K miles and a 15 quarts sump.

The wear metals dropped because the last two OCIs are half as much or less in mileage. On a "per mile" basis they are all about normal.

Those are some really expensive OCI/UOA cycles. He's paying for some premium fluids, and not getting anywhere near his ROI (presuming normal costs apply).

Swithing to Rotella 15w-40 is probably a very good idea for his area. His temps and OCIs do not warrant synthetics. He will save a LOT of money if he just OCIs every 5k miles with quality dino oil. I would suggest that he run one OCI with Rotella, but NOT UOA on that load; let the chemistry changes normalize. Then do another load of the Rotella and then he can take a UOA sample.

I agree with AZsynthetic; that's a lot of oil going somewhere in such short OCIs ...

He's losing burning a LOT of oil there-for example, the '04 E-350 6.0 PSD I drive every day maybe goes through 1 quart in 5,000 miles-and that's approaching 260K. It'll be interesting to see if the consumption improves with the 15W40.

If he does alot of short trip driving where the engine isn't up to temp hardly at all then that could explain some of the oil loss. The pistons haven't expanded all the way in a cold engine so it gets past the rings.

Makes sense!

I know he has a leaky oil pan but it wouldn't cause that much oil burn.