2004.5 Dodge 5.9 - Scheaffer 15w40 - UOA 31,000km

Aug 12, 2022
First time poster. Learned a lot over the years here at bitog, thought I'd add my findings for others to learn from.

Here is my latest uoa from agat with past history. 4L make up oil. Truck goes through about 1L every 5000km on average, but uses mainly when towing. AL may seem high, but when I did a VOA on this oil, it started at 3

Full flow filter is Donaldson DBL7349. Neither full flow or bypass were changed. ( I've cut the donaldson open, and I would have no concerns running that filter for much longer)

I changed the oil today at 42,000km. Wear metals and TBN looked fine, but oxidation and viscosity had me concerned.

I hotshot travel trailers with this truck. So all highway and half towing. Current goal is to reduce oxidation and subsequent thickening so I can achieve a 60,000km interval. I've seen mention that 25abs/cm-1 is the condemation limit for oxidization, can others confirm this? This 15w40 is a para synthetic, I'll be switching back to the full syn 5w40 (for winter) after I run out of this 15w40. Though I won't get a proper comparison until running schaeffer syn 5w40 next year in the hot summer. Also considering adding a secondary oil cooler, but I will first wait and see on how the 5w40 fairs.

Note about history: Before april 22' i was running schaeffer 5w40. I was also running a smarty tuner until april 22'; sold it because my uoa were showing high soot and wear.