Quote:
Originally Posted by RustyLugNut
Modern vehicle systems 20 years advanced of what is found on your truck are beginning to use EGR to grab the few percent efficiency gains found in the so called "b.s. theory". And, you mix diesel theory with spark ignition operation. They are two different stories.
And the pollution mechanism for NOx also includes solar activation of NOx to Ozone - a far more long lived pollutant at ground level. That is the brown haze seen in valleys like Los Angeles and Denver. Even when not visible, the concentrations are elevated near any metropolis.
But, you are right, these topics are very broad and beyond the scope of this thread.
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Agreed. I guess my point was that in 1997, the technology was available (and had been for 10 years) to manufacture a vehicle that didn't need an EGR or AIS to pass federal emissions standards, especially for a heavy-duty vehicle (which had much less stringent standards than passenger vehicles at the time). EGR and AIS are throwbacks to the early 1970's when the big 3 were struggling to meet the requirements of the Clean Air Act and the newly created EPA. EGR was never introduced or intended to help fuel economy and any theoretical gains in the lab are irrelevant and insignificant in the real world. I also understand that the economics of manufacturing plays a big part here. Why spend the money on more advanced means on controlling emissions in 1997? Gas was around $1 a gallon and most consumers that were contemplating the purchase of a one-ton pickup most likely had fuel economy low on their list of priorities.
The comparison with what has happened with Diesel technology was just to demonstrate the economics of manufacturing something that is regulated by an institution that is so far detached from the real world (remember when the EPA wanted to regulate dust produced from dirt roads? And CO2 is now considered a pollutant.) that the manufacturers are forced to engineer technology into vehicles for emissions regulations that have nothing but negative impacts on fuel economy (the EPA's standard of 'grams per mile' is biased towards smaller cars and engines).
It's been a while since I took any college level chemistry but I'm pretty sure the 'brown cloud' is from NO2 (nitrogen dioxide). I DO remember some lab experiments with nitric acid that went very wrong and copious clouds of acrid red/brown smoke being produced. Not sure what the mechanism of reaction between NOX and ozone (O3) is but I know there are reactions between HC (unburned hydrocarbons) and ozone. BTW, ozone is not something found in internal combustion engine exhaust. Ground level ozone is mainly produced by the reaction of VOC's in the atmosphere in the presence of ultraviolet light. It is also produced by lightning and the simple reaction of UV light on oxygen.
But before I drift too far off topic, the goal with my old F350 is to match the fuel economy of my friends 2014 EcoBoost F150. I may not be able to get to 24mpg but I bet I can get close. And spend a lot less than $42,000 to do it.
Maybe there needs to be a new thread on what the impacts of emissions control technology and how to make improvements to those systems while improving fuel economy at the same time.