No More DPF "Dosing"

[Keith Browning]

So I completed the web-based NMT. One of the interesting features of the vehicle and the 3.2L Diesel is the fact that the aftertreatment DPF regeneration  does not use dosing for regeneration. There is a fuel vaporizer and a glow plug located before the DPF and it uses it's own fuel pump. This is a departure from what most Ford guys are used to seeing. I think educated consumers will see this as a good thing as dosing is not looked upon as favorable.  

[tonybullitt]

I didn't understand this aftertreatment system having both the fuel vaporizer and scr system. So I was reading thru the pc/ed description and operation. It states the fuel vaporizer is there to heat up exhaust and regenerate filter. The scr is to reduce NOx. The only difference to a 6.7 I see is instead of injecting on exhaust stroke we have a fuel vaporizer to inject fuel for heat needed. Wonder why the need for fuel vaporizer  instead of injecting on exhaust stroke? Because of it being a 5cyl? Because of exhaust valve issues on 6.7?

[jimmy57]

I would think it is due to fuel build up in oil that exhaust injection has always had as a side effect. Exhaust valve stress might be a part of it.  If the Transit was used in heavy city use then the regens could be frequent and the fuel dilution in oil would be a problem if introduced in cylinder.

The move to additional injector in pipe has been widespread in commercial diesel engines.

[Cetane]

Having DSI does reduce the dilution problems caused by non-torque forming injections but it is mainly due to the relatively low-tech fuel system.  

 

I am sure you all remember the pilot injection fiasco on the 6.0L. Cheaper injectors generally mean less injection events possible per cycle.  Apparently somebody learned their lesson and didn't try to overtax them.