cwerdna
Well-known member
Very interesting.... thanks!drees said:The conspiracy theorist in me found this news article somewhat coincidental...
German automotive companies launch “clean-diesel” marketing campaign in US
Very interesting.... thanks!drees said:The conspiracy theorist in me found this news article somewhat coincidental...
German automotive companies launch “clean-diesel” marketing campaign in US
Stoaty said:Well, a 90% reduction in particulates is a big improvement, but how do those particulate figures compare to, say, a Prius? Does a Prius emit any particulates? In other words, are we talking about clean (relative to ICE), or just cleaner than in the past?mrradon said:REF INFO:
Diesel Sulfur Content (PPM):
1994-2007: 500
2007-Present: 15
Particulate Matter (g/hp-hr):
1994-2007: 0.10
2007-Present: 0.01
Nitrogen Oxide (g/hp-hr):
1994-1998: 5.0
1998-2002: 4.0
2002-2007: 2.5
2007-2010: 1.2
2010-Present: 0.2
Europe apparently has a tax structure (from what I understand) that makes diesel cheaper than gasoline, the opposite of the US most of the time. Fuel prices in Europe are FAR higher than the US, so people are more likely to gravitate towards high FE... and for whatever reason, it seems they're less likely to feel the "need" to buy battering ram of death class SUVs, for consumer/personal use.mrradon said:In all new diesel emission technology makes them much better power sources then gasoline engines. Europe has proven that.
That chart says it all:cwerdna said:Re: CO2 and GHGs, take a look at the # of tons per year in tailpipe CO2 or tailpipe & upstream GHG of these cars: http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=31767&id=31575&id=31585&id=32092&#tab2" onclick="window.open(this.href);return false; under the Energy and Environment tab.
I wouldn't be surprised if some or all of these were going on: those cars have way less hp (and worse acceleration) than would be tolerated in the US (and thus wouldn't sell here), mis-conversion from l/100 km into miles per larger Imperial gallons, you were going slow and/or hypermiling, those cars would be illegal for sale in CA and possibly the rest of the US.mrradon said:I see the fuel economy in the spec's as 30/42 for the Jetta TDI. I know for a fact last year my German Hertz rental Audi A3 got 50 city, 58 Hwy on a 3,500 km road trip (converted from l/100km).
I know for a fact my cousin's TDI Golf (two years ago) got about 55 for the trip to Gibraltar and back, with (2) wind surf boards and sails on top. (we weren't cruising +130kph).
I know a Prius would have gotten far far far less on this road trip, I've rented the darn things in CA and the leave lots left to be desired.
For a given volume of fuel burned, burning diesel does emit more CO2 than burning gasoline. http://web.archive.org/web/20110203045034/http://www.epa.gov/otaq/climate/420f05001.htm" onclick="window.open(this.href);return false; has more details. But again, this has no relationship to the EPA smog/air pollution score.One last fuel-economy tidbit: Don’t even think of comparing EPA figures with standÂardized fuel-economy tests from other countries because the test cycles are very different. For example, the European highway rating, called “extra urban,” is higher than the EPA’s by about 30 percent, so a rating on that cycle of, say, 60 mpg, would be closer to 40 in this country. The mainstream press, not realizing the difference, often complains that automakers refuse to bring efficient models here when, in fact, they may not be all that efficient when measured by U.S. standards.
But, I've already pointed out to you numerous tests that the TDI vehicles available in the US get worse mileage than the Prius. Even if they got equal mileage, the diesel would still emit more CO2.cBeam said:Bottom line is that a Diesel engine will use less Diesel than a comparable gas engine uses gas (assuming that other conditions are comparable). You should let go of the issue that burning one unit of Diesel produces more CO2 than one unit of gas, this has only to do with the higher energy content of Diesel
We've already established that "clean diesels" do worse on EPA air pollution/smog scores. And, in test results, some pollutants are an order of magnitude higher the Prius.cBeam said:Please be aware that nowhere above I write about "clean". Wherever you burn fossil fuel it is not clean. And if burning Diesel or gas is cleaner depends on your definition of clean, and how engine manufacturer implement technologies to make exhaust less "dirty".
We've already established that this isn't the case either. CR's highway test (last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf" onclick="window.open(this.href);return false is run at a constant 65 mph. The Prius achieved 55 mpg. The TDIs achieve 45 to 51 mpg on that test, depending on the car and transmission.cBeam said:If you want to compare efficiency of a Prius to a TDI, again it is a little more complex than meets the eye at first.
...
If you drive a Prius over a long distance on a level road without accelerating and decelerating, the Prius' efficiency will be determined almost entirely by the efficiency of its gas engine. Under this (theoretical) condition the hybrid part of the Prius contributes nothing, on contrary. Assuming you have a low traffic highway where you can drive constant speeds over a long distance, this is where a TDI outperforms a Prius in real world driving in terms of efficiency.
On their above highway test, the Prius hit 50 mpg while the TDI got 42 mpg.For highway mileage we drove freeways across Michigan from Ann Arbor to Holland and back, 337 miles between fills. Traffic hustles along these days. We drove 75 to 80 mph where possible, at the upper range of flow.
cBeam said:cwerdna, here are the latest fuel consumption numbers (first number is city, followed by out of city (highway), third is a combined value)
Golf TDI (77 kW) 4.6 / 3.3 / 3.8 l/100km
Prius (73 kW) 4.0 / 3.8 / 4.0 l/100km
For both brands these are self reported numbers derived from a mandatory test cycle. Real life consumption numbers are worse, however each manufacturer for sure did his best to come up with the best possible consumption numbers.
Looking at these numbers is becomes evident what I tried to explain to you earlier: A well designed hybrid performs very well in city traffic or traffic with frequent acceleration and deceleration. Driven on highways with constant speed the electric part of the hybrid does not contribute any more, and consumption is only dependent on the ICE. This is where the Prius burns 3.8 l/100 km, while the TDI uses 3.3 l/100km (about 15% less). This establishes that a TDI uses less fuel than a Prius when driven over long distances with constant speed.
I am not sure if you can buy the Golf TDI in the US, for sure you can buy the Golf TDI or the Prius in Germany.
I guess your confusion stems that you try to compare apple to oranges. All things equal a modern Diesel engine is more efficient than a modern gas (Petrol) engine. This is what I tried to explain to you. Can we establish that? It's basic physics, nothing else: Carnot Cycle.
A car is as efficient as the sum of its part. If you put the Prius Synergy Drive into a Hummer, the efficiency of the "car" will go south, in the city because of the weight, and on the highway mainly because of the wind resistance of the Hummer. In this case a 20 year old BMW will consume less fuel than the Hybrid Hummer.
And back to "Clean": If you use EPA's definition of clean, then you have the numbers. If you use a different definition you will compare different numbers. If you compare a clean ICE to the tailpipe emissions of an electric car, you will agree that the cleanest ICE does not look that clean anymore.
Source of these numbers? You can buy a Golf TDI in the US but not w/only 77 kW (103 hp). The ones here are 140 hp (http://www.vw.com/en/models/golf/trims-specs.html" onclick="window.open(this.href);return false. This goes back to Herm's statement about acceleration and mine.cBeam said:cwerdna, here are the latest fuel consumption numbers (first number is city, followed by out of city (highway), third is a combined value)
Golf TDI (77 kW) 4.6 / 3.3 / 3.8 l/100km
Prius (73 kW) 4.0 / 3.8 / 4.0 l/100km
For both brands these are self reported numbers derived from a mandatory test cycle. Real life consumption numbers are worse, however each manufacturer for sure did his best to come up with the best possible consumption numbers.
Looking at these numbers is becomes evident what I tried to explain to you earlier: A well designed hybrid performs very well in city traffic or traffic with frequent acceleration and deceleration. Driven on highways with constant speed the electric part of the hybrid does not contribute any more, and consumption is only dependent on the ICE. This is where the Prius burns 3.8 l/100 km, while the TDI uses 3.3 l/100km (about 15% less). This establishes that a TDI uses less fuel than a Prius when driven over long distances with constant speed.
I am not sure if you can buy the Golf TDI in the US, for sure you can buy the Golf TDI or the Prius in Germany.
Yes, diesels are generally more efficient and use less fuel than non-hybrid gasoline powered vehicles.cBeam said:I guess your confusion stems that you try to compare apple to oranges. All things equal a modern Diesel engine is more efficient than a modern gas (Petrol) engine. This is what I tried to explain to you. Can we establish that? It's basic physics, nothing else: Carnot Cycle.
cwerdna said:Hybrid Synergy Drive hybrids and many other hybrids get increased ICE efficiency due to them using the Atkinson cycle .
It is the very finest soot – so small that it lodges deep within the lungs and from there enters the bloodstream – that contributes to most of the public health toll of air pollution including mortality. Diesel soot, which is also a carcinogen, is a major problem because it is concentrated in cities along transportation corridors impacting densely populated areas. It is thought to contribute to half the premature deaths from air pollution in urban centers. For example one in six people in the U.S. live near a diesel pollution hot spot like a rail yard, port terminal or freeway.
Yes the Prius is SULEV. Even non-hybrids are SULEV, just by adjusting their tuning to run richer and emit less NOx. It's isn't that difficult.downeykp said:This does not even take into consideration a Prius is a hell of a lot more comfortable car to drive in and is less polluting.
If you buy a newer CA spec '12+ Volt, it gets a 9 on the smog score. See http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=31618&id=32655&#tab2" onclick="window.open(this.href);return false; and http://green.autoblog.com/2011/11/16/new-enhat-pzev-chevy-volt-ready-for-california-hov-access-extra/" onclick="window.open(this.href);return false;.theaveng said:For all the talk of TDIs "only" getting a 6 on the smog score..... the Chevy Volt hybrid also gets "only" a 6. And most on this forum would consider that a clean car.
Then why don't they esp. if can be done "without barely trying"? Re: diesel Focus meeting PZEV standards, source? I see no diesel Focus being sold in the Us at all.theaveng said:As I've mentioned before a VW diesel could get a PZEV rating too (that's a 9 on EPA's smog scale) without barely trying. Run the engine richer and the NOx drops the 0.5 g/mile needed to get the CARB certification. It isn't difficult. It's how Ford got their diesel Focus to meet PZEV standards.
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