Quote:
Originally Posted by TheGrimMechanic
I don't disagree with the original principles of the EPA. It's my opinion that what has happened over the years is that the EPA has been turned into a political tool and doesn't have the best interests of the country as one of its core values. I agree that there is some success' but recently it's gone overboard in some areas. My complaint don't entirely center on the EPA itself but also the rules it creates and leave up to the states to define or enforce or the unreasonable burdens placed on manufacturers and even the general consumer. Here are a few examples (albeit not related to the original intent of this post);. . .
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Some of what you say is true, and some of it is just opinion and much if it is just wrong. But, your discussion is thoughtful and fruitful and is worth the time to read and digest. The readership hits attest to that, so please do not see my answers as being derogatory or undermining. I think you will agree we want the same thing - economical trucks that are clean and simply fun to drive. You approach the emissions problem from your point of view, whereas I see it as an opportunity for a business model that is growing beyond the AQMD region.
I will start with the rail industry. It has been discussed on this and other forums as to how efficient it is to move goods via rail. 450 Ton miles per gallon are just a starting point. No ship, plane or truck even comes close. Thus, it was not seen as one of the "low hanging fruit" targets. But, now it is. In the next few years, you will see fewer heavy polluting engines as the new and rebuilt engines will have increasingly stringent emission controls. The funny thing is, with almost 30 million people in the affected zone, the millions of tiny lawn mowers and weed whackers which have disproportionate emissions output for their size roughly equal the emissions output of the large rail heads which pass through Southern California. Due to the longevity of some of these devices and also the fact that there is no reasonable way to "test" for compliance, all the EPA can do is require all new devices to comply with the simple strictures of sealed fuel systems and tighter factory tuning for less emissions and allow , via attrition, the reduction of emissions from this source over a couple decade span! The emission improvements the rail companies will employ between 2015 and 2025 will see emissions output from rail engines drop below that of small motor sources in all criteria pollutants other than the controversial CO2. The increasing use of battery electric motors to replace the internal combustion engines that dominate the small engine industry may help alleviate the problem as long as Ecomodders leave some batteries for the lawn care guys.
And heavy duty trucks such as yours and mine and all the way up to Class 8 tractors were outnumbered roughly 100 to 1 by light duty vehicles, thus they were left alone for decades. By the mid 90's, cars were so clean that the output of one heavy duty truck roughly equaled the emissions from 200 cars. As light cars have become cleaner, this disparity has grown, and so heavy trucks came under scrutiny.
Emission controls for diesels is in its infancy.
Diesel Particulate Filters (DPF) work and they work well. However, some problems with light duty drive cycles have given them a bad name. We have a 2008 Dodge Cummins 6.7 L diesel which has a DPF as a company truck. It has never needed a DPF cleanout as it's sole use is to tow a 20,000 pound trailer. The DPF constantly runs hot enough to purge itself without the purge cycle light going on. A lady on YouTube has the same vehicle and is getting names for a class action suit against Dodge and Cummins for selling a faulty vehicle. She is a soccer mom who never does any heavy towing. Her DPF is constantly running cool and cannot even initiate a purge cycle so the DPF clogs up and she is constantly at the dealer getting cleanouts. So, are DPF's faulty? Well, as Oil Pan 4 pointed out in another post, drive cycles has a lot to do with system effectiveness.
As to EGR ( Exhaust Gas Recirculation ) in diesel engines, the technology is mature, but the use by several manufacturers of EGR only diesel engines gave it a bad name. Again, our Dodge Cummins uses cooled EGR and a DPF to control particulates and NOx. As I pointed out above, if the DPF is run consistently hot enough, you can get 100-200K miles from it before clean out or replacement. Our truck is at 249K miles and is only down because an experimental engine is going into it - and it has never needed a DPF service. Much of it has to do with over all service of the truck. The injectors are inspected once a year as a precaution during top end adjustments. Drippy injectors cause poor economy and clog a DPF quickly. While that is done, we also have the EGR and turbo cleaned up and tested. Poor boost causes over fueling conditions and smokey engine output which quickly clogs the DPF. Now, the problem becomes the EGR. EGR causes an increase in particulates under certain load conditions even though it reduces NOx. This increase in particulates results in a loss of efficiency and power. There is no other way to say it, but "it bites".
Bring in Diesel Emissions Fluid (DEF) which is nothing more than anhydrous ammonia. It does not work by itself. It works in conjunction with a NOx trap. Nitrogen oxides are held by the trap's matrix until it is purged by conversion (reduction) of the NOx via decomposition of the ammonia into N2 and hydrogen and the hydrogen's reduction of the NOx to N2 and water. The inclusion of this system to a diesel engine allows you to now tune your engine for higher efficiency with less EGR along with a reduction in particulates. This means fewer purge cycles for the DPF and better fuel economy. However, you now have to deal with the costs and bother of another fluid.
So where can we go from here? Old Mechanic has repeatedly brought up the work of Transonic Combustion and their advanced injection system. Such a system will allow diesel combustion with little to no particulate production as well as such rapid combustion that NOx formation is minimized. All of this results in cleaner exhaust before any after-treatment is needed as well as improved power and economy.
As I have said, I don't fear emission controls, I relish it. Emissions tell me my engine is wasting energy in producing pollutants. By building an engine that minimizes pollutants internally, I can have an engine that is both more powerful and economical.