CAT recommended oil for PC engines

I was reading the PDF http://parts.cat.com/cda/files/3244668/7/SEBU6250-19.pdf that Old Magnet and others have been discussing and I found a reference to Precombustion chamber oil or PCO available in 40 weight. No other information about it. There is a warning to not use single viscosity oils in Direct injection type engines manufactured after 1990.

So I searched online for Caterpillar Precombustion chamber oil and found this (appears to be newer? ) CAT publication which deals specifically with Precombustion chamber type engines on page 17. http://parts.cat.com/cda/files/3244668/7/SEBU6251-16.pdf It specifically says CAT PCO is acceptable to use in PC type engines and also says PC engines can also use multi viscosity oils recommended for DI engines, BUT not the other way around.....ie PCO in a DI engine.

There appear to be several CAT specifications applicable to these oils ECF-1a, ECF-2 and ECF-3. Chevron DELO 400 SAE 15W40 API CI-4 which we use here meets the ECF-1a and ECF-2. ECF-3 is for Tier 4 engines with DPF etc? Probably best not to use the CJ-4 spec oils in oder engines with flat tappet cams etc because they are formulated with low additive levels to reduce emissions and may not protect against sliding friction as well as the older CI-4 spec.

I think those of us that use our tractors in cold weather will readily appreciate the benefits of using multi viscosity oils as opposed to straight 30 or 40 weight, but to each his own😆

It's the polymers that make up the multi-viscosity oils that are an issue with PC engines. Read all of this.....

I read it twice?
Still don't see any referance to the polymers.
Only CAT Marketing stating superior SOOT control.

If you read through the second document I linked to there is a section about marine engines that mentions turbocharger fouling from polymers in the oil and soot buildup on the transom of the boat.

Somehow I am not so sure these documents really consider engines as old as what most of us have.😆

The specific warning about not using multi grade oils in those series marine engines is for those engines where the crankcase blow-by is routed into the intake. This is at the bottom of page 14.