# Are U.S. diesel buyers getting triple screwed?



## Squiddie (Dec 19, 2010)

This has been bothering me for a while.

Both gasoline cars and diesel cars get piled on with restrictions and more restrictions.

However, is the treatment of diesels actually fair? It looks to me like the relevant government agencies simply put on restrictions and regulations for gas and diesel independently, regardless of which one "needs" it more.

Or in other words: I don't think that the diesels get the break they would deserve because their base fuel consumption is lower. If you wanted to bring diesel and gasoline to the same overall environmental impact you would need more regulations on gas. But that isn't what is happening. They both get cracked down on independently.

I am also convinced that the reason why BMW now picked a small 4 cylinder diesel for the 3-series in the US market is mostly driven by a desire to lower the fleet consumption. Which comes down to image/marketing and again to regulations. I don't believe for a minute that anybody inside BMW actually thinks that US buyers would voluntarily pick the 4 cylinder engine over the 6 cylinder one. It's a BMW and fuel is cheap in the US. They would buy the 335d.

The third strike on the dieselheads is the general restrictions on model variety. I cry every time I visit a European building website and looking at all the engines they can get. I don't cry as much over the prices, granted. It is really not clear to me whether government regulations (paperwork) or dealer lot size reductions are the main driver here. I mean BMW makes a large percentage of these cars on demand anyway. I understand they want the dealers to have a chance to sell a car off the lot, but is this a problem the European dealers don't have?

I have to say that these antics get a bit out of hand.


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## floydarogers (Oct 11, 2010)

Squiddie said:


> This has been bothering me for a while.
> 
> Both gasoline cars and diesel cars get piled on with restrictions and more restrictions.
> 
> ...


Actually, both gasoline and diesels are operating under the SAME restrictions. EPA restrictions (but not CARB) are designed around NOx, HC, CO pollutants and have nothing to do with CO2/mileage. The emissions systems on diesels are designed to bring the diesel emission to the same level of cleanliness as gasoline.

Well, duh, regarding mileage. BMW is under the gun because it's customers are used to fast cars.

Model variety is due to a regulatory bottleneck (somewhat because of historical reasons). It costs a lot (~ $5M) per model to certify in the US/CA. BMW, being a low-volume manufacturer, can't sell enough low-volume models and keep the prices competitive while amortizing that cost, unless they're high-priced cars like the X6/7-series/M3/M5/etc.


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## wxmanCCM (Feb 17, 2010)

It has been my contention for some time that EPA/CARB developed Tier 2/LEV II emission regulations around what gasoline vehicles were technically able to meet, and diesels were left to fend as best as they could. This has resulted in very complicated and expensive after-treatment required for diesel vehicles (there's nothing "magical" about Tier 2/LEV II emission regulations from an air quality perpective).

There are also some other obstacles to diesels in the U.S....


- higher federal fuel tax on diesel fuel
- unrepresentative drive cycle mix even according to EPA itself
- under-representative official fuel economy results for diesel relative to actual real-world mileage
- loophole for "running loss" VOC emissions for gassers
- EPA's "Smog Rating" unrepresentative of true "smog" potential
- carpool-lane access


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## O8 BMW (Apr 7, 2013)

Bottom Line. A diesel will cost a few thousand more to buy. Cost of disposal should be a few thousand more than a gasser, because it's a diesel after all. Right now in my neck of the woods, diesel and premium are at the same price, about $4.00 per gallon, providing me with a 25% to 30% savings in fuel cost compared to gasoline. I get better torque and a cool sounding car. With mostly highway driving, I am coming out ahead. If I drive mostly in city or in heavy traffic the cost per mile difference would be a wash. I average 25 - 26 miles per gallon. At $4.00 per gallon that's $0.15 per mile. Not bad... so I don't think I am getting hosed at all.


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## stevehecht (Apr 13, 2007)

wxmanCCM said:


> It has been my contention for some time that EPA/CARB developed Tier 2/LEV II emission regulations around what gasoline vehicles were technically able to meet, and diesels were left to fend as best as they could. This has resulted in very complicated and expensive after-treatment required for diesel vehicles (there's nothing "magical" about Tier 2/LEV II emission regulations from an air quality perpective).
> 
> There are also some other obstacles to diesels in the U.S....
> 
> ...


Good to see you've still got your nose in these here parts. 

Aren't the second and third bullet points above essentially describing the same thing?

Also, what do you mean with the last bullet point? What does that have to do with obstacles to diesels in the U.S.?

And (if you don't mind), what's the technical backround on the next to last point concerning smog potential? I don't understand how that discriminates against diesels.


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## Kamdog (Apr 15, 2007)

Plus, the Sawx are off to a lousy start. Getting their butts kicked by the what-is-his-name? Yankees?

Geeez.


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## F32Fleet (Jul 14, 2010)

Squiddie said:


> This has been bothering me for a while.
> 
> Both gasoline cars and diesel cars get piled on with restrictions and more restrictions.
> 
> ...


Yes and no.

#1 Diesel is taxed higher because trucks use it as fuel and it is trucks that put the most wear and tear on our roads.

#2 Per barrel of crude oil you can make more gasoline than diesel. On a macro scale this negates the efficiency gains that diesel has over gas (ex. 30 mpg gasser vs 40 mpg diesel probably use approx. the same amount of crude oil per X miles).

#3 Since gas is so cheap compared to Europe US Consumers won't overpay for low hp diesels.


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## wxmanCCM (Feb 17, 2010)

stevehecht said:


> Good to see you've still got your nose in these here parts.
> 
> Aren't the second and third bullet points above essentially describing the same thing?
> 
> ...


Steve,

Those two bullet points probably are related, but the point I was trying to make in the second bullet point is that EPA uses a 55% city/45% highway duty cycle mix for calculating the "combined" mileage, which is NOT the average drive mix currently in the U.S., even according to EPA itself. It's actually 43% city/57% highway based on EPA data, and is the duty cycle mix used in its mobile source emissions model ("MOVES").

The point about under-representation of fuel mileage is more related to how EPA calculates both the city and highway mileage. It uses a correction factor which includes "ethanol in gasoline". Of course, ULSD doesn't contain ethanol, so there's at least one error in the calculation. If you'd like to see more about the bias in fuel economy metrics against diesels, take a look at the EPA publication at http://www.epa.gov/carlabel/documents/420r06017.pdf - pages 3 and 8.

Should have been more clear about the last bullet. There is no jurisdiction of which I'm aware that permits single-occupancy diesel cars to use the HOV lanes, in spite of the fact that this type of driving would be most beneficial for diesels in terms of fuel efficiency. EV and even hybrids are permitted in some places to use HOV lanes in spite of the fact that it's not where they are most advantageous in terms of fuel efficiency - stop and go driving is where HEV and EV excel. The lack of HOV lane access is actually borrowed from an article from _Automotive News_ - http://www.autonews.com/apps/pbcs.d...29969/germans-renew-diesel-push#axzz2dkZiCtIR.

For the point about unrepresentative "smog ratings", here is a graphical comparison of emissions from the 1.8 liter PZEV gasoline and ULEV diesel versions of the 2014 VW Passat, including the smog-precursor emissions, NMOG and NOx. The "smog ratings" are "9" and "6", respectively...










...Even the vehicular emissions (blue portion of bar in graphic) are lower across-the-board for the TDI. Futher detail is available at http://webpages.charter.net/lmarz/emissions2014.html. Bottom line is that diesels are FAR lower with respect to smog-precursor emissions regardless of "smog rating", even if you consider NOx and NMOG to be equally potent in smog production, and there's a myriad of studies which conclude that NMOG/VOC is much worse than NOx in smog production (gasoline in the primary source of NMOG/VOC in urban areas).

Let me know if you have any questions or require further information.


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## UncleJ (May 7, 2006)

Great chart! Now, I hope the diesel hating eco-Nazi's at CARB will read it. It is my firm contention that CARB has an institutional bias toward diesels. I don't know why, but I would bet that the ageing flower children who run that (and most other state departments here) have a deep seated antipathy against what they perceive to be the smoke belching busses and cars of the 60's when they were in the Haight Ashbury.:angel:


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## floydarogers (Oct 11, 2010)

UncleJ said:


> Great chart! Now, I hope the diesel hating eco-Nazi's at CARB will read it. It is my firm contention that CARB has an institutional bias toward diesels. ... the smoke belching busses and cars of the 60's when they were in the Haight Ashbury.


The real problem, until 2006, was the high sulfur in the diesel, which contributed to the bad-ass SO2 and PM emissions. Europe understood that and went to ultra-low sulfur several years earlier to help remediate their air quality after they essentially forced the market there to go diesel with taxes.

And you shouldn't totally discredit CARB: they're the ones that are requiring ~53 cetane in many peoples' diesel!

Not saying I don't like the cleanliness of current diesels, but the DPF and oxydation catalyst are *almost* all that's needed.


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## mattebury (Feb 2, 2014)

UncleJ said:


> Great chart! Now, I hope the diesel hating eco-Nazi's at CARB will read it. It is my firm contention that CARB has an institutional bias toward diesels. I don't know why, but I would bet that the ageing flower children who run that (and most other state departments here) have a deep seated antipathy against what they perceive to be the smoke belching busses and cars of the 60's when they were in the Haight Ashbury.:angel:


Since this is a 2014 model comparison with all the modern emission requirements, I'm sure that CARB is quite pleased to see that diesels are on par with gasoline, except for CO. Also, I'd like to see the stats behind those charts and whether or not the differences posted in the graph are statistically significant, in other words, except for CO emissions, both cars appear to be equal in emissions from the tailpipe.


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## wxmanCCM (Feb 17, 2010)

mattebury said:


> Since this is a 2014 model comparison with all the modern emission requirements, I'm sure that CARB is quite pleased to see that diesels are on par with gasoline, except for CO. Also, I'd like to see the stats behind those charts and whether or not the differences posted in the graph are statistically significant, in other words, except for CO emissions, both cars appear to be equal in emissions from the tailpipe.


That's actually a chart I produced via xcel. The link I provided in my previous post gives the methodology behind the graphic. The calculations and assessment are mine, and I request that any errors noticed be brought to my attention.

The point I was trying to make is that the Passat 1.8T is certified PZEV and is given a "smog rating" of "9" by EPA (and CARB). The Passat TDI is certified ULEV and gets a "smog rating" of "6" by EPA and "5" by CARB. In fact, the overall emission profile of the TDI certainly isn't any "worse" than the 1.8T, and actually is "better" across-the-board, even if only slightly. Thus, the "smog ratings" are unrepresentative of the true "smog" forming potential of the respective vehicle emissions.


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## mattebury (Feb 2, 2014)

wxmanCCM said:


> The point I was trying to make is that the Passat 1.8T is certified PZEV and is given a "smog rating" of "9" by EPA (and CARB). The Passat TDI is certified ULEV and gets a "smog rating" of "6" by EPA and "5" by CARB. In fact, the overall emission profile of the TDI certainly isn't any "worse" than the 1.8T, and actually is "better" across-the-board, even if only slightly. Thus, the "smog ratings" are unrepresentative of the true "smog" forming potential of the respective vehicle emissions.


Without knowing what the formula is that qualifies one car as a "5" and the other a "9," it's tough to see if one is being unfairly treated compared to the other. The only thing I can think of that would make a diesel score lower than a gasser is increased CO2 emissions, doing the rough calculations on an 8-chain hydrocarbon v a 12-chain hydrocarbon (simplistic I know). Diesel puts out about 2.5% more CO2 by mass than gasoline (i.e. 1kg of gasoline burned compared to 1kg of diesel). Is the EPA using tailpipe CO2 emissions in their calculation?


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## wxmanCCM (Feb 17, 2010)

Here is the scale according to EPA...

http://www.fueleconomy.gov/feg/findacarhelp.shtml#airPollutionScore

It's not really a formula as such, just a relative score based on vehicle emissions (and on the category/bin a vehicle is certified to). Note that the "smog score" does not include GHG.


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## mattebury (Feb 2, 2014)

Basically, comparing scores across "bins" is meaningless. But since the average consumer does not understand that . . .


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## wxmanCCM (Feb 17, 2010)

mattebury said:


> Basically, comparing scores across "bins" is meaningless. But since the average consumer does not understand that . . .


Exactly!


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## UncleJ (May 7, 2006)

Yes CARB did give us the 53 cetane diesel -- but they also gave us MBTE too and we all know how that turned out. The point about the ultra low sulfur is a valid one and is probably the only reason we are able to drive the new generation oilers here at all.:thumbup:


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## F32Fleet (Jul 14, 2010)

UncleJ said:


> Yes CARB did give us the 53 cetane diesel -- but they also gave us MBTE too and we all know how that turned out. The point about the ultra low sulfur is a valid one and is probably the only reason we are able to drive the new generation oilers here at all.:thumbup:


I just wish BMW had figured out how to run a diesel with only DPF and SCR and WITHOUT EGR.


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## stevehecht (Apr 13, 2007)

wxmanCCM said:


>


wxman,

I think a graph like this comparing a diesel engine (say, for the 328d) with a Prius would be really interesting. You sent me some preliminary numbers on this in a PM a while ago, so I wonder if you'd take a shot at it. If I remember correctly, the 328d held up quite nicely against the Prius in a WTW comparison.


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## wxmanCCM (Feb 17, 2010)

Steve,

Here's what I get for the 2014 328d and 2014 Prius (AT-PZEV) based on CARB certified emissions for "pump to wheels" (PTW) and EPA emission factors for "well to pump" (WTP)...










HC = NMOG for the purposes of this graphic

I used the GREET1_2013 default PTW PM2.5 emissions since PM is not provided for the Prius and not specified as PM2.5 for the 328d. It should also be noted that I did not include the evaporative emissions from the Prius, which would add ~0.008 g/mi to the HC+NOx PTW portion of the bar.


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