Übersicht: Peugeot - 308 - Spritmonitor.de 308 fails to even get close to NEDC in real world. Diesel is a fake CO2 "saver", but owners persist in MPG+lower fuel cost benefits. A nice car, but not an award-winner, doesn't bring anything new... A bad moment for COTY prize...
The EU isn't nearly as concerned with NOx emissionss as the U.S. is ... ironically ... because they were leaders in low sulfer fuels. We limit NOx (iirc) to 0.05 grams per mile which is ⅛ of the 0.40 limit in the EU. So, all you gotta do to find one vehicle better is discount a certain type of pollution ... then, it's all good. .
The new Peugeot 308 diesel that gets 91 mpg UK combined (97 mpg UK Highway rating) complies to the latest Euro6 emission controls that apply to new models released in 2014. So it has a maximum NOx of 0.08 g/km though many cars will be lower than this. The 0.40 g/km figure you quote for the EU applied to the year 2000 Euro 3 standard! Things have moved on since then Page 8/12 confirms which models meet Euro 6 and which meet Euro 5; http://www.peugeot.co.uk/media/peugeot-308-prices-and-specifications-brochure.pdf Euro emission standards; European emission standards - Wikipedia, the free encyclopedia Update: I've just looked at the Wiki link and it appears you were quoting the Euro 6 standard for BUSES!
How does diesel "fake" the CO2 number? The EU is directly measuring the exhaust..... no way to cheat that. 82 g/km beats even the hybrids. (Another poster also proved you wrong on the NOx which is below 0.08.). By the way why is NOx considered bad? The human body makes its own NOx internally, so it isn't really a poison. (shrug)
NOx is shorthand for both NO and NO2 From Wikipedia: Nitric oxide - Wikipedia, the free encyclopedia Nitric oxide, or nitrogen oxide,[2] also known as nitrogen monoxide, is a molecule with chemical formula NO. It is a free radical[3] and is an important intermediate in the chemical industry. Nitric oxide is a by-product of combustion of substances in the air, as in automobile engines, fossil fuel power plants, and is produced naturally during the electrical discharges of lightning inthunderstorms. In mammals including humans, NO is an important cellular signaling molecule involved in many physiological and pathological processes.[4] It is a powerful vasodilator with a short half-life of a few seconds in the blood. Long-known pharmaceuticals such as nitroglycerine and amyl nitrite were discovered, more than a century after their first use in medicine, to be active through the mechanism of being precursors to nitric oxide. Low levels of nitric oxide production are important in protecting organs such as the liver from ischemic damage. Nitric oxide should not be confused with nitrous oxide (N2O), an anaesthetic and greenhouse gas, or with nitrogen dioxide (NO2), a brown toxic gas and a major air pollutant. However, nitric oxide is rapidly oxidised in air to nitrogen dioxide. Humphry Davy discovered this to his discomfort, when he inhaled the gas early in his career. Notice that NO2 is a brown toxic gas? Mike
NOx can be a precursor to smog. Other things can cause smog though. In a few localities, more NOx might actually keep those others from forming smog. In the US, diesels are held to the same standards as gasoline cars, and many exceed the base limit. They also have a particulate requirement that gas cars currently don't have to adhere too.
What trollbait is referring to is this: The contours on the plot show ozone concentration (smog) vs. NOx and VOC concentrations. The maximum formation of smog requires a balanced supply of VOCs and NOx. If you are in the bottom right portion of the graph you are "NOx limitted", ie there are surplus VOCs floating around without a NOx molecule to react with. In this region, ozone concentration will track directly with NOx concentration, so reducing NOx reduces smog. If you are in the top left area of the graph, you are "VOC limitted", ie there is surplus NOx floating around without VOCs to react with. In this region ozone concentration will vary much with NOx levels, and toward the top of the graph can even decrease with increasing NOx. Here is a map that indicates typical summer VOC/NOx ratios in the US. While NOx reduction is a good thing, I think this data also points to the importance of reducing VOCs particularly in urban areas. This is why you tend to see those vapor capture thingies show up on the gas pumps in cities with smog issues. Diesels tend to put out more NOx, but have less unburnt hydrocarbons and much lower evaporation emissions due to the lower volatility of the fuel both contributing to lower VOCs. Gasoline engines tend to have higher VOC emissions but less NOx. With the soot issues becoming more of a draw between modern diesels and modern gasoline engines, I don't think there is a real clear argument one way or the other on emissions any more. Rob
For any fellow data geeks out there, this is an amazing website Test Car List Data Files | Cars and Light Trucks | US EPA Rather than just looking at the emissions cert levels, you can see the actual test levels measured for each vehicle certified within a given year.
It get more to the gallon but I believe that diesel has more energy per gallon and thus produces slightly more CO2 for the same gallon. That's how a less economical hybrid gets a lower g/km CO2 figure than a diesel that would get more to the gallon. I'm guessing that the diesel matching the g/km of a hybrid is ever so slightly better in that it will go further for your £'s. The diesel Peugeot is also the same size as the Prius and shouldn't be compared to the much smaller Yaris hybrid which actually gets slightly less to the gallon! I remember 4 years ago when I got my Prius and people would compare it to the small diesel hatchbacks that got the same mpg's. Now things have turned round. We're comparing small hybrid hatchbacks to larger diesel cars that go further on an expensive gallon on fuel. But the thing everyone is forgetting is that it doesn't really matter which is better, but that BOTH cars are getting amazing mpg's and the more cars that get such economy should be encouraged! The Peugeot is a mainstream car. It is one of a growing number that will now exceed the Prius (and even the Yaris hybrid) for mpg's and match it on emissions.
NEDC can be "forced" by many ways, and real figures give you a good reason to question manufacturer's numbers. Very high tyre pressures, best tyre available at less width, bit worn, a very warm engine, etcetera... Opel Insignia 2.0CDTI 120hp is the latest actor: 99g/km announced... Overview: Opel - Insignia - Spritmonitor.de (average 5.85l/100km - 40.1MPG) The lesser emitter Details: Opel - Insignia - 2.0 CDTI Ecoflex Start/Stopp - Spritmonitor.de is 143g/km by average! To get 99g/km, it should average 3.76l/km (62MPG US). Offset 44% (real divided by rated). Prius averages 5.12l/km (45.8MPG US) - 119g/km Overview: Toyota - Prius - Spritmonitor.de Rated 89 or 92g/km, Offset 29%.
Does it? Overview: Peugeot - 308 - Spritmonitor.de Peugeot 308 5.4 l/100km Prius 1,8 5.12l/km Emissions... Peugeot 308 142g/km Prius 1,8 119g/km
France pulls a lot of weight in the EU and Peugot pulls a lot of weight in France. Doesn't take a genius to figure out what's going on there. Same reason Jeremy Clarkson on Top Gear craps on hybrid vehicles - Europe doesn't make one. About time someone told him his precious Aston Martins are being recalled due to faulty Chinese parts.
Rob, Thank you for your post. Very informative. One comment about the graphic you included. I have a hypothesis that biogenic VOCs are fundamentally different than anthropogenic VOCs in net ozone production in that most biogenic VOCs are ALKENES, e.g., isoprene, pinene, while anthropogenic VOCs tend to be alkanes, e.g., octane. Alkenes actually readily react with ozone, while alkanes are essentially nonreactive with ozone (but a decomposition product (peroxy radical) is very reactive with NO, which interferes with the NOx photolytic cycle and results in net ozone production). As such, it is my opinion (and I've never seen any studies conducted regarding net ozone production of alkenes vs. alkanes) that anthropogenic VOCs and biogenic VOCs behave differently in ozone production chemistry (i.e., there's some direct ozone destruction with biogenic VOCs). I can only offer my own (unpublished) study that I conducted while still employed at NOAA as empirical evidence. My study compared the ambient NOx concentration at Look Rock, Tennessee (a very remote site within the Great Smoky Mountains National Park - expected to be very NOx-limited, according to the graphic in your post) with the ambient ozone concentration. The result showed a very weak correlation (R^2=0.07) between ambient NOx concentrations and ambient ozone concentrations over the 2010 ozone season. Unfortunately, the AQ monitor at Look Rock doesn't include a VOC monitor, so ambient VOC concentrations are not known exactly. The graphic accompanying the study is posted at tdiclub.com at http://pics.tdiclub.com/data/500/Look_Rock_Ozone_vs_NOx.png if anyone is interested. I could be totally wrong, but there appears to be some remote locations that don't behave like a typical NOx-limited location would be expected to behave with respect to net ozone production.
Clarkson is a dick. So France pulls weight in the EU and that's why there are no Euro hybrids eh? Check out the Peugeot website and you'll find they offer three hybrids. They were also the first in the World to offer a diesel hybrid that only costs a few grand more than the Prius, has 209 bhp and emits 99g/km. Peugeot were also one of the first European companies to offer a BEV. Peugeot Model Range They'll also about to release a petrol/compressed air vehicle hybrid! This works similar to a hybrid but doesn't need a battery and will get 117 mpg UK on the Euro test cycle and emit 69g/km. Check out this; Peugeot-Citroen unveils compressed air hybrid tech | Autocar You might want to check the facts in full first
If you feel bored, try to seek Peugeot 3008 hy4 and 508RXH on Spritmonitor... ...can't wait for the compressed air to teach Toyota how to innovate...
