Thanks for mostly repeating me. A DPF without SCR is pretty much the worst setup you can get. That's basically an on-road setup from 2008-2012 which are known to burn massive amounts of fuel and have bad reliability problems with the DPF. Comparatively common rail with EGR and DOC is an early 2000s setup which are very robust. If you can meet the emissions requirements without the DPF, there's no reason to have it, whether it's overall cleaner or not, especially without SCR.
Well, it certainly is true the Ford 6.4L had this type of system and had a lot of problems. Possibly others. It was still the early days of DPFs. Yet today, most non-road diesel under 75HP is operating with a DPF and EGR and no SCR. I've had two Kubotas including my current one; there is no issue. Fuel consumption is just fine.
Not true, Bosch knew exactly what was going on and allowed it. This is well documented.Bosch is a hardware provider. They're not responsible for implementation and programming.
Primarily caused by Ford and GM not properly specing the vehicle fuel filtration system to meet the pump requirements. Other applications of the CP4 with proper filtration work just fine. Basically if any pump fails you're going to have massive fuel system damage. nature of the beast.
I can't speak for GM but all Ford diesels with the CP4 have always used two fuel filters, a frame mount and engine mount, with a water drain on the frame mount. I've often heard your argument made regarding improper filtration, but it simply isn't true. Having owned both, there's not much difference other than the ones in the Ford are a whole lot easier to access.
Wasn't aware of the Duramax swap, but that still leaves a large portion of diesel applications that use it, including a big chunk of European manufacturers. I knew Cummins had swapped to the CP4 for a variety of reasons, again with no known problems, probably because the Ram setup has dual fuel filters, one rear frame mounted with water separator and one front engine mounted.
VW TDI engines have also had fuel pump failures. They use a single piston version of the CP4. I don't think the CP4 is a wholly bad pump, but there is no doubt it has a poor reliability record when contrasted to the previous CP3. RAM will be equally vulnerable to failures. If you pumped a bad load of diesel with a high water content, eventually the separator fills and the water moves forward to the pump. By the time the WIF light comes on, the event is recorded in the PCM and warranty can be denied on that basis alone.
If Kubota uses it, good for them, they're ahead of the curve, although I'm unaware of any particular reason you have to have it. I never said it was anything special, just that it's a preferred engineering solution to an emissions requirement over other fixes. If your controls are programmed correctly you can meet emissions without the problematic DPF. Multiple injection events give multiple burn initial conditions, controlling both mixture and combustion temperature to reduce both soot and NOX. Looking at some of the designs, it appears as if DPF is being used as a bandaid to avoid changing the engine substantially.
There are novel injector designs but none are currently in production. With ever increasing emissions requirements, some sort of a filter is going to be necessary, even with extremely clean combustion. It is still combustion, after all.