The older 7.3 IDI in my sig does fairly well using a blend of 15W40 & some NextGen MaxLife 10W40, carrying a CF rating, to slow down the oil cooler & rear main leakage somewhat-but I'm not going to push it past 3000 miles or so. My 300D had been abused by long OCIs using Castrol GTX when I bought it-to the point that the compression was suffering due to soot clogging the rings, but Mobil 1 TDT helped that quite a bit. In my (limited) light-duty diesel experience, it's the ability of HDEO to agglomerate (collect) soot so that the oil filter can catch it that is the big factor, along with higher ZDDP levels (but newer low SAPS HDEO oils have a lot less of those, obviously not as critical).
What will happen if...
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This is exactly what I used in my old 123 diesels.
An API CF 10W-40 seemed fine for these low performance NA engines.
These things would soot-load the oil pretty heavily, but Mercedes also called for very short drains, 3K IIRC, so that along with the generous sump capacity meant that it probably didn't matter.
An API CF 10W-40 seemed fine for these low performance NA engines.
These things would soot-load the oil pretty heavily, but Mercedes also called for very short drains, 3K IIRC, so that along with the generous sump capacity meant that it probably didn't matter.
Yep, it seems that plenty of CF era diesels called for fairly modest OCIs, to the point that I would insist on greatly extending them using something like an E7/E9 lube. My dad's 7.3 L called for a 3,000 mile OCI with that very large sump, too. I'm sure 3,000 miles on a 10w-40 CF would be fine, but substantially longer on a good CJ-4 would be better, or at least much cheaper.
That supports what I found running GTX 10W40 last winter in my 2011 Duramax.
After 20% left on the OLMS, the UOA soot content was not even on the chart yet.
But, I have not yet duplicated the fuel economy the 10w40 PCMO achieved
with other engine oils.
I'm holding out for PC-11 to fix that.
After 20% left on the OLMS, the UOA soot content was not even on the chart yet.
But, I have not yet duplicated the fuel economy the 10w40 PCMO achieved
with other engine oils.
I'm holding out for PC-11 to fix that.
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Hi,
perhaps my contribution was off beam - I thought the OP was comparing PCMOs to HDEO's when in OTR trucking. Most of these engine from Euro or US sources are above 11 litres and operate in a different world to diesel engines in cars
Most OTR heavy diesel engines today have a first design life of around 2m kms when serviced/maintained correctly, and when using only OEM specified lubricants
perhaps my contribution was off beam - I thought the OP was comparing PCMOs to HDEO's when in OTR trucking. Most of these engine from Euro or US sources are above 11 litres and operate in a different world to diesel engines in cars
Most OTR heavy diesel engines today have a first design life of around 2m kms when serviced/maintained correctly, and when using only OEM specified lubricants
I pay a lot of attention to ACEA specs and MB specs, much less to SAE specs (CI4+, CJ4, etc). I have an HD engine - a MB 906LA.
I think it would be idiotic to run a VW507 oil (ash
Charlie
I think it would be idiotic to run a VW507 oil (ash
Charlie
But something like M1 0W40 has a much higher TBN and is IMHO more suited for HD diesel use, with good dispersant and ZDDP level.
Charlie
Charlie
Originally Posted By: Doug Hillary
perhaps my contribution was off beam - I thought the OP was comparing PCMOs to HDEO's when in OTR trucking. Most of these engine from Euro or US sources are above 11 litres and operate in a different world to diesel engines in cars
I think your point was spot on. Whether it's OTR trucking or a mid 1980s GM 6.2 L diesel, running the appropriate lube is important. As you mentioned, that older API stuff was none to spectacular and certainly predated the noticeable split between API diesel and API gasoline/ILSAC lubes. An old 6.2 L diesel is obviously different than the latest Duramax or what we see in OTR trucking.
For people making their living from their trucks, proper maintenance is that much more important, as you've shown us time and time again.
perhaps my contribution was off beam - I thought the OP was comparing PCMOs to HDEO's when in OTR trucking. Most of these engine from Euro or US sources are above 11 litres and operate in a different world to diesel engines in cars
I think your point was spot on. Whether it's OTR trucking or a mid 1980s GM 6.2 L diesel, running the appropriate lube is important. As you mentioned, that older API stuff was none to spectacular and certainly predated the noticeable split between API diesel and API gasoline/ILSAC lubes. An old 6.2 L diesel is obviously different than the latest Duramax or what we see in OTR trucking.
For people making their living from their trucks, proper maintenance is that much more important, as you've shown us time and time again.
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