Quote:
Originally Posted by bawareca
Well said  I am on the same mindset as you on these matters. Now there are a few "ECO " questions:
-all the diesel "emission" systems result in a higher consumption,it may be 4-6 MPG for the US X5D over ROW models.Is the net result really pro-ECO,or just a local cleaner air in the cities? |
It is undoubtedly a net positive. Particulate filters take out up to 90% of the particulate matter. Diesel particulate matter has been shown to be very harmful to human health. According to the Californian authorities, "long-term exposure to diesel exhaust particles poses the highest cancer risk of any toxic air contaminant evaluated by OEHHA. ARB estimates that about 70 percent of the cancer risk that the average Californian faces from breathing toxic air pollutants stems from diesel exhaust particles."
If you increase consumption 5 mpg it increases pollutants by around 15%. If you then treat the exhaust and take out 90% of the pollutants, you are way ahead, on a net basis.
The smog component relates to NOx, not particulates so much. NOx is reduced by the urea injection. Removing the urea system and disabling the selective catalytic reduction increases smog.
It is difficult to directly compare the US regulated X5D with the ROW models. The US focuses on NOx because of the contribution to smog. Europe focuses on CO, because of the contribution to climate change. The vehicles have been optimized for different criteria. What is greener? Probably driving a much smaller, lighter vehicle, and driving less. There isn't much to choose between one 5000 lb diesel vehicle with a single occupant (most of the time) and another.
Quote:
Originally Posted by bawareca
-Generally,the DPF collects the soot and releases it(regeneration)while burning some of it.It is released back in the atmosphere after all.According to many experienced BMW diesel tuners,with DPF removed,this engine will emit very slight HAZE out of the exhaust under hard acceleration only.No blowing black smokes out of the tailpipe in any way.
-as we all know now the problem with the HP EGR,is it worth it all the damge it is causing when failing ?
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The regeneration cycles burns the soot, it doesn't release it.
Quote:
Originally Posted by bawareca
DPF off may be a more radical solution,EGR delete has so many benefits that I cant even start counting. It may net over $2k savings in the span of 40-50 k miles.Not even counting the headaches  |
In my opinion, that makes a good case for any fines to be many times the potential savings.
This discussion illustrates one aspect of why it took so long for diesels to come to North America, on regulated vehicles (ie lower GVWR than HD pickups). The manufacturers were concerned that people would defeat the systems (as was the EPA) and so the systems were made even more complicated (and thus less reliable) to try and thwart tampering.
I am with Ard in that I have an issue with defeating emissions controls. IMO, if the current solutions offered by manufacturers have more problems than they are worth, then that is a very good reason not to purchase a diesel. It isn't like there aren't alternatives.