Attention: TDR Forum Junkies 
OK, I may have found my limits of CJ-4 Rotella 15w40 dino... keep in mind this truck is more/less stock in the realm of things.
Back in September 07, the Wife and I went on a 5500 mile trip to the Rockies with the camper. Did some long hard pulls, had just installed an EGT guage so I kept things in check. I did a before UOA and after UOA... the after indicated the oil had degraded slightly, however wear metals were considered normal for the usage (towing). I changed the oil after the results came back, even though they were considered fine for continued use. The main thing that popped out was the oil had thickened. Keep in mind, this was towing about 3500#s (slide in and small utility trailer), so it wasn't HD towing like others do.
Shortly after, I lost an injector, all were found leaking... blah, blah, blah. I never did change that fresh oil, continued to run it a few months, did a UOA and results were fine... oil looked good. I changed the bypass element and added 1. 5 gallons of make up oil (this means I changed 33% of the total volume)... the oil was still in fine shape (as viewed at the dipstick).
I took this oil to Washington a couple weeks ago... the oil never changed characteristics until I was outrunning some storms on the way back... conditions for the oil were probably considered "severe" as I was averaging around 80mph, almost 1000*F EGTs, around 25psi boost, and around 2800RPM... I was running about a 45mph headwind. This hell run lasted from just south of Minneapolis to DesMoines. I checked the oil at the very next fuel stop... it had changed to resemble that oil I drained after my Rockies trip. Keep in mind, the truck was empty for this trip... I doubt I had more than 300#s in the bed.
After the Rockies, I attributed that oil's condition to the failed (or failing/leaking) injectors. Now I'm not so sure. I'm probably going to pull a UOA tomorrow and verify my visual findings, but I'm confident the oil will come back with an increased viscosity (you can tell it is thicker without much scrutiny). Soot is not a factor as insoluables have came back at 0. 4% or less every UOA.
So I guess its time for a change... based on recommendations I'm probably going to either wait for CJ-4 Rotella 5w40 to appear on shelves (so I don't have to do another change later on) or run 5w40 Schaeffers, both are synthetic variants.
I don't think this newer CJ-4 likes heat... that seems to be the only variable. And don't get me wrong, what I've done to this oil is nothing compared to what some people are doing towing their RVs.
Again, these are my findings and may not represent Rotella in all trucks, just mine.
Back in September 07, the Wife and I went on a 5500 mile trip to the Rockies with the camper. Did some long hard pulls, had just installed an EGT guage so I kept things in check. I did a before UOA and after UOA... the after indicated the oil had degraded slightly, however wear metals were considered normal for the usage (towing). I changed the oil after the results came back, even though they were considered fine for continued use. The main thing that popped out was the oil had thickened. Keep in mind, this was towing about 3500#s (slide in and small utility trailer), so it wasn't HD towing like others do.
Shortly after, I lost an injector, all were found leaking... blah, blah, blah. I never did change that fresh oil, continued to run it a few months, did a UOA and results were fine... oil looked good. I changed the bypass element and added 1. 5 gallons of make up oil (this means I changed 33% of the total volume)... the oil was still in fine shape (as viewed at the dipstick).
I took this oil to Washington a couple weeks ago... the oil never changed characteristics until I was outrunning some storms on the way back... conditions for the oil were probably considered "severe" as I was averaging around 80mph, almost 1000*F EGTs, around 25psi boost, and around 2800RPM... I was running about a 45mph headwind. This hell run lasted from just south of Minneapolis to DesMoines. I checked the oil at the very next fuel stop... it had changed to resemble that oil I drained after my Rockies trip. Keep in mind, the truck was empty for this trip... I doubt I had more than 300#s in the bed.
After the Rockies, I attributed that oil's condition to the failed (or failing/leaking) injectors. Now I'm not so sure. I'm probably going to pull a UOA tomorrow and verify my visual findings, but I'm confident the oil will come back with an increased viscosity (you can tell it is thicker without much scrutiny). Soot is not a factor as insoluables have came back at 0. 4% or less every UOA.
So I guess its time for a change... based on recommendations I'm probably going to either wait for CJ-4 Rotella 5w40 to appear on shelves (so I don't have to do another change later on) or run 5w40 Schaeffers, both are synthetic variants.
I don't think this newer CJ-4 likes heat... that seems to be the only variable. And don't get me wrong, what I've done to this oil is nothing compared to what some people are doing towing their RVs.
Again, these are my findings and may not represent Rotella in all trucks, just mine.
