William Chops Westfield wrote: > On Dec 18, 2006, at 11:09 AM, Tachyon wrote: > > >>> Diesel is bad news for air in the US. Europe may have diesels that >>> are >>> as clean as gas but over here they are all, Mercedes included, really >>> dirty. The EPA OTAQ WWW page has an excel spreadsheet with every >>> single >>> model. The jetta is worse than a 3/4 ton Suburban. >>> > > >> What is the basis of your Jetta vs Suburban statement? >> > > Presumably here: http://www.epa.gov/greenvehicles/ > >> The EPA ratings are based on mostly effect on human health, not on >> environmental impact. Certainly this is important, but also can be >> misleading when trying to compare technologies. >> > > Right. Greenhouse gases, regardless of whether they are a real problem, > are not traditionally what makes a vehicle "dirty." The above EPA site > puts the greenhouse emissions in a separate category. > > >> Engine MPG Cty/hwy Yearly greenhouse >> Jetta >> 1.9L Diesel 36/41 5.6 tons >> 2L Premium Gas 25/31 6.7 tons >> 2.5L 5cyl reg gas 22/30 7.4 tons >> Chevrolet Suburban >> 5.3L gas 15/20 10.6 tons >> 5.3L E85 11/15 8.6 tons >> 6L Gas 14/18 11.3 tons >> Accord Hybrid/reg gas 25/34 6.6 tons >> Mercedes E320CDI >> 3.2L Diesel 27/37 7.0 tons >> >> > > It looks to me like those greenhouse numbers are based directly on > the milage, which makes sense. Gas vs Diesel getting about the same > milage have about the same greenhouse emissions. CH2(n) fuels, eh? > > Maybe, but you get a lot more work per MPG from a diesel. For example, how many people and how much luggage can a gasoline powered vehicle carry that gets the same MPG as the Mercedes E320 CDI BlueTec? It makes more sense to compare similar vehicles based on MPG and emissions. That's why I put the Lincoln in with the Mercedes. Note that that is the old E320 CDI, not the BlueTec. >> The fact is that diesel is cleaner than gasoline in almost all aspects. >> > > There appears to be some conflicting data on that :-) > Or perhaps "except in all past and current implementations." > None at all. In comparable vehicles and engines, a diesel produces less emissions in all but NOx and particulates. That's not speculation, that's tested fact. > >> Especially in important greenhouse gas emissions. >> > > I don't think you can elevate "greenhouse gases" to "more important > than other pollutants" all that easily. It's controversial enough > to raise it to 'as important as'... > I elevate it because it's the greenhouse gases that are harder to reduce. In that regard it gives diesel an advantage in being simpler to clean up. Where as gasoline engines are already at the edge of their envelope for efficiency. It will be difficult to wring lower greenhouse emissions from gasoline engines. > >> this will change with the newly mandated low-sulphur diesel. >> >> > Sure it will. Show me. > It already has. There's nothing to show. The only thing that diesel has needed to be cleaner than gasoline is for the greedy US refineries to get off their butts and produce a better quality, low sulphur diesel fuel. It didn't happen so the government finally forced them to and it's in pumps now. With the upcoming BIN5 emissions regs taking effect in 2009, diesel will be _required_ to be cleaner. Given that diesel is already cleaner in all but NOx and particulates, and that BIN5 specifically requires lower NOx and particulates, then therefore, all 2009 diesel vehicles will be cleaner than gasoline vehicles or they won't exist. Pretty simple logic. Mercedes has already done it with the BlueTec and the 08 BlueTec powered Mercedes, Jeeps and Chryslers will meet BIN5. BIN5 will be the most stringent vehicle emissions in the world, so I imagine every country will benefit from manufacturers having to meet BIN5 in the largest automobile market in the world (for now). Add the fact that diesel is more efficient, provides better fuel efficiency, and engines tend to have greater longevity, the consumer benefits as much as the environment. > BillW > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist