Prospects for Light-Duty Diesels in the US
23 August 2006
On paper, clean advanced technology diesel passenger cars and light-duty trucks should be charging into the US market. The changeover to Ultra Low Sulfur Diesel that takes affect this year—a profound change akin to the removal of lead from gasoline, according to the EPA—opens the door to advanced emissions aftertreatment controls that can meet tough US emissions regulations.
The torque and power of diesels should appeal to US drivers, and the increased fuel economy of diesels compared to current gasoline counterparts should appeal to drivers as well.
But while acknowledging all of the above and stating that they are planning diesel introductions into the US market, a panel at DEER 2006 comprising GM, DaimlerChrysler, BMW, Honda, Volkswagen the EPA and the Martec Group also noted some major hurdles to a rapid proliferation of diesel models in the US.
A common worry shared by the automakers is that the costs associated with overcoming some of the issues will further increase the price of diesels, reducing the economic incentive for buyers. Should the price of oil collapse, they worry about the potential for a repeat of the diesel boom and bust of the 1980s.
The technical hurdles can be grouped into two basic categories which are inter-related:
- Emissions compliance, specifically the NOx limits; and
- Fuel quality.
Emissions. The US Tier 2 regulations—which are converging with California LEV regulations—are the toughest in the world. A future Euro-5 diesel passenger car won’t qualify for Tier 2 Bin 5. Automakers are developing advanced combustion regimes with associated reductions in engine-out NOx and aftertreatment systems to hit the target.
On the NOx front, Lean NOx traps (LNT) and urea SCR systems are the leading approaches automakers are exploring. LNT has limitations in efficiency that make it less suited for larger vehicles and in durability, and urea SCR faces the fundamental issue of getting the EPA on board with its use, given potential issues with compliance. (How, in other words, do you ensure that drivers replenish the urea to ensure that the emissions aftertreatment system continues to work?)
Fuel quality. The variable range and threshold of some properties of US diesel fuel raises a number of issues for the automakers. For example, US diesel cetane numbers range from 38-58; European numbers range from 50-60. US aromatics can range from 13% to 50%.
The wide range and lower threshold of centane numbers drives a need for a variety of engine modifications, including more EGR, and more cold starting aids on the engine, according to Ford’s Brien Fulton in a separate presentation at DEER. High aromatics also increase engine deposits, EGR deposits and exhaust system deposits. These, and other factors, limit the synergies with European diesel powertrain technologies for the US.
The automakers. Of the automakers participating in the panel, GM was the least committal toward a product direction.
Diesel powertrains satisfy unique vehicle requirements in utility and large vehicles, but the economic payback diminishes as you go down in vehicle class...the proportion of the financial improvement diminishes, and it becomes more of a challenge to bear the cost of powertrain additions that go along with the diesel technology.
Not seeing a clear solution to meeting Tier 2 Bin 5 requirements, GM has been reluctant to introduce a vehicle.
In principle, if diesel is ever going to be widely accepted as a fuel solution in North America, it needs to be seen as comparable to its gasoline counterparts [in terms of emissions]. That ultimately is where we need to be. As long as there is a perception that diesel is an exception, it will never be widely accepted by the regulatory community or consumers.
—Michael Potter, Chief Engineer, Diesel Technology, GM Powertrain-Europe
DaimlerChrysler, which is outspoken about its BLUETEC technology framework as being the “Tier 2 Bin 5” enabler (earlier post), is nonetheless primarily relying on Bin 8-compliant introductions over the next year. A big consumer factor for DaimlerChrysler is the image of diesel.
For an expanded diesel market, the image has to be right. If we are going to go into the mainstream, we’re looking at regular sedans and SUVs...it’s very important to get the image right.
—Simon Godwin, DaimlerChrysler Manager for Regulatory Affairs
BMW is planning on diesels in both its sedans and SUVs for North America, and has sketched out a Tier 2 Bin 5 approach that relies on modified combustion, an advanced EGR system, an adapted fuel injection system, new control devices, additional sensors, OBD functions, a DPF and urea SCR system.
Wolfgang Mattes, BMW’s director of functional development, was particularly concerned about the problem of On-Board Diagnostics that meet US requirements.
We need some compromises to get diesel in [to the US market], such as the phase-in period for OBD.
—Wolfgang Mattes
Honda, given its recently announced strategic direction to use diesel powertrains for fuel-efficiency in its larger vehicles, was very bullish about its technical approach (earlier post) as well as on the potential benefits of diesel.
We want to contribute for clean diesel technology as we have for the gasoline engine.
—Yasuyuki Sando, Honda Senior Manager Advanced Powertrain
Volkswagen has been selling diesels in the US for more than 25 years. Diesels currently constitute about 15% of its US sales.
[Diesel] will succeed by delivering increased efficiency, reduced CO2 emissions, high levels of performance, and being the best platform for renewable fuels including biodiesel, sunfuel and sundiesel.
—Klaus-Peter Schindler, Volkswagen
Schindler noted that diesels will compete against and have to coexist with other technologies, including advances in gasoline engine technology, the success of hydrogen, and the potential public focus on long-term solutions, such as hydrogen.
Mike - thanks for providing updates on presentations from the DEER conference.
Posted by: Carl | 23 August 2006 at 09:47 AM
"Honda...was very bullish about its technical approach as well as on the potential benefits of diesel."
..."bullish"
?????
Posted by: John W. | 23 August 2006 at 09:54 AM
Should the price of oil collapse? LOL!!!! Everyone start shorting the oil market!!! :)
Posted by: Chingy | 23 August 2006 at 10:11 AM
A price collapse is still in the realm of possiblity. But I think it's unlikely to fall very far.
And "bullish" means "positive". They think the market will grow. I'd buy a Honda diesel, myself. And probably will once it's on the market.
Posted by: Cervus | 23 August 2006 at 11:00 AM
"For example, US diesel cetane numbers range from 38-58; European numbers range from 50-60. US aromatics can range from 13% to 50%."
_Perhaps the large profits oil companies (specifically those with refinery ops) have been racking up should be spent on rectifying this issue. It should also go towards getting 15ppm ULSD in place sooner, and <10ppm ULSD online quickly afterwards. More refinery capacity and the activation, enlargement, update and upgrade of closed down refineries is a further place to spend their cash. After all, we are lacking reinery capacity.
_
___Biodiesel and various blends of it may be the ticket for less particulates, though NOX will have to be dealt with.
Posted by: allen Z | 23 August 2006 at 11:28 AM
<15ppm sulpher is here already. It's at many pumps right now and mandated for something like 50% adoption by October. The article states the problem is the wild variance in cetane and aromatics. Agreed with others to take some of those tens of billions in profits and reinvest in properly refining it to a tight cetane window, like +/- 5% of 55 cetane, and a fixed aromatics figure like 15%.
Posted by: Sid Hoffman | 23 August 2006 at 12:13 PM
My dream car (as a replacement for my wife's Accord): The new, still-unnamed, 2009 hybrid-only Honda is a plug-in clean diesel hybrid that gets about 120MPG.
Right now that sounds like it's bordering on SciFi, but all the pieces are here or will be very soon.
Posted by: Lou Grinzo | 23 August 2006 at 12:17 PM
"Should the price of oil collapse, they worry about the potential for a repeat of the diesel boom and bust of the 1980s."
That's BS. Diesels went bust in the 1980s because GM put too much trash on the market. We are still living with the consequences today.
I want a small turbocharged diesel driving a hybrid.
Posted by: Lucas | 23 August 2006 at 02:32 PM
Lucas, it's not BS about diesels going bust in the 80's. Yes, GM's 350 V8 wasn't developed properly, and it created a PR problem. But what about all the other manufacturers who were selling lots of diesels in the late 70's early 80's? Mercedes was almost all diesel then, and by 85 had almost none. VW, Peugeot,etc. had been selling lots of diesels during the high fuel price era, but when oil went bust and prices came down, their buyers almost all evaporated. Let's face it, all diesels were noisy, smelly and slow then. In the face of cheap gas prices, interest in diesels evaporated. The GM issue was just another nail in the coffin.
Posted by: pauln | 23 August 2006 at 03:09 PM
Who knows what will happen with the price of oil? But what I want to know is the image of diesels that consumers have in the USA. Many remember the smelly, noisy, and dirty diesels of the 80s. Can automakers overcome this image?
Posted by: Mark R. W. Jr. | 23 August 2006 at 03:18 PM
In 1981 I bought a 1981 Isuzu Diesel Pickup. According to the mpg sticker and the salesman I was supposed to get 41 mpg. Never even got close.
Neigbor was a lawyer. He bought two GM diesels. Left one in California when it blew up. Gave the other one back to GM. His threat to file suit got him a full refund.
You couldn't get him to even think about a GM or diesel now.
It's a lot more than image.
Posted by: Lucas | 23 August 2006 at 06:50 PM
The GM Diesels from the early 80's were half baked and total garbage. Then again that was 25 years ago and so I would say that those incidents have anything to do with modern diesels except they were diesels. Gail Banks makes big reliable power out of GM's Duramax diesels so I guess they've come a long way.
Posted by: Tim Russell | 23 August 2006 at 07:36 PM
Sid and Lou, I seldom hear anyone advocating a plug-in diesel-electric hybrid. That is also my dream car. It would work perfectly for my nice short commute to work. I would love to scrap my brake rotors and add regenertive braking.
I also agree that it is time to employ the existing technology for 100+ mpg diesels.
Credible people are forcasting that crude oil will approach $30/ barrel before $100/barrel. I am not in the industry so I don't know.
Even if oil prices decline it would still be nice to get 100 mpg. I really don't like sending all that money to the middle east every time I buy fuel.
I would not be at all surprised if Honda figures out a good solution to NOX polution and then gobbles up market share with an Accord type diesel.
I think consumers realize that the diesel automobiles that are being sold now are better than the ones in the 1980s. The gasoline powered cars were not exactly reliable back then either, but people still buy gas cars. Millions of people buy diesel pick-up trucks. They all know the benefits of diesel.
Posted by: Jon | 23 August 2006 at 07:44 PM
Actually right before the end of production, the GM V8 diesel had been developed into one hell of a good engine. In its final form it displaced about 396 cubic inches, and it was fitted with a special injection pump whose wearing surfaces were coated with teflon. The horsepower was derated to enhance its long term reliability. It was called the Fuel Miser Diesel, which when fitted in a 7 ton chassis(the kind they use in bread delivery trucks; etc,) with a 4 speed Allison Automatic transmission and a differential gear ratio of over 6:1 was rated to get 39 M.P.G.!
It quite simply was utterly revolutionary.
Unfortunately, the emission control legislation mandated by the good old Clean Air Act of 1991 (with the support of all the good enviromentalists, of course) doomed it. This is just another good example of E.P.A. emission controls screwing up diesel fuel economy, and causing this country to import much, much more oil than is necessary.
Posted by: Dave Zeller | 23 August 2006 at 07:57 PM
Dave, the engine you are refering to was a completely different engine. The lemon diesel was based on the Olds 350 engine (5.7 liter). The truck engine was designed from scratch to be a light truck engine, and the later turbo-charged version is what every miltary Humvee and other light trucks uses. It wasn't doomed by the EPA; it was sold in Chevy/GMC light trucks until it was replaced by the much more advanced and powerful direct-injection Duramax engine. The older engine is still being installed for military Humvees. By the way this engine was never installed in passenger cars. GM did make a 4.3 liter V6 diesel that had (to my knowledge) a good rep, but by then GM had vlown it with the 5.7. For what it's worth, if fuel prices had stayed high in the 80's, GM would likely have developed the 5.7 car diesel to become reliable too. But dropping gas prices made it irrelevant.
Posted by: pauln | 23 August 2006 at 09:33 PM
Dave Zeller wrote:
Unfortunately, the emission control legislation mandated by the good old Clean Air Act of 1991 (with the support of all the good enviromentalists, of course) doomed it. This is just another good example of E.P.A. emission controls screwing up diesel fuel economy, and causing this country to import much, much more oil than is necessary.
Dave, are you proposing that we should breathe dirtier air, and all be driving these great diesels? There are plenty of cars today that get great mileage and have clean engines. You sound pretty dismissive of the EPA and "all the good environmentalists". Are you one of those guys who don't care how many children grow up with scarred lungs as long as you can save a few bucks on fuel? The name of this blog is Green Car Congress, I might point out.
Posted by: George | 23 August 2006 at 10:01 PM
Are you one of those guys who don't care how many children grow up with scarred lungs as long as you can save a few bucks on fuel?
This question is akin to "Have you stopped beating your wife?" And it's an appeal to emotion, a logical fallacy. At some point the costs associated with emissions reductions outstrip the benefits in reduced risk of health problems. You will never be able to reduce the health risks to zero, nor will you remove every last particle of soot from diesel exhaust. It's not a perfect world.
Posted by: Cervus | 23 August 2006 at 10:59 PM
At some point the costs associated with emissions reductions outstrip the benefits in reduced risk of health problems.
Really? What point is that? Tell us where it is.
It's not a perfect world.
Speaking of logical fallacies... yeah, it's not a perfect world. I think everyone knows that. That doesn't mean we then don't try to make improvements.
Posted by: Joseph Willemssen | 24 August 2006 at 12:20 AM
"Are you one of those guys who don't care how many children grow up with scarred lungs as long as you can save a few bucks on fuel?"
Hmmmm, these pollution controls constitute an improvement in our health? I'll try to explain it like this using a comparison.
A 7 ton class Mitsubishi truck (previously discussed on the website a few months back) using a 2.8L diesel equipped with the latest EPA mandated pollution controls will only achieve around 11 m.p.g.
An obsolete 7 ton GM Fuel Miser will achieve 39 mpg. It does this whilst producing pretty much the same horsepower as the Mitsubishi.
The Mitsubishi, per mile, burns fuel at a rate 3.54X that of the "polluting" Fuel Miser. In other words, if both commercial vehicles are driven 100,000 miles per year, the GM would burn 2564 gallons of fuel, and the Mitsubishi will go through 9090 gallons of that nasty sulfur-laden stuff!
Could someone here tell me how in the hell an engine that pukes out the exhaust resulting from the combustion of 3.54X the fuel than is really necessary is considered more healthy and "green" than that which burns the least?
Shall we refer to this as "The Death of Common Sense"?
Posted by: Dave Zeller | 24 August 2006 at 03:22 AM
US diesel fuel quality will hopefully be addressed as more diesels penetrate the US auto market. We need to address poor fuel quality in order to reduce the cost of using diesels. The lower the quality of fuel, the more sensors are going to be needed to adjust engine electronics to optimize emissions. Why not improve the fuel quality and reduce the cost of usage and purchase (less post combustion treatment needed). An ultra premium grade can be refined by GTL (no sulfur and high cetane) from natural gas. Unfortunately, it appears we still look at diesel in the US as a tractor fuel.
Posted by: Craig | 24 August 2006 at 05:14 AM
George, et al, if diesel engines are so bad for air quality, why doesn’t the air quality statistically improve on weekends (yes, I’m bringing up that pesky weekend ozone effect again) when diesel truck traffic has been shown to decrease by as much as 80% (http://www.osti.gov/fcvt/deer2005/lawson.pdf)? Not only don’t ambient ozone levels improve, but I see no evidence that ambient PM2.5 levels improve significantly. This is based on EPA monitoring data (see http://www.airnow.gov/index.cfm?action=airnow.archives&RegionID=0). And this pre-dates the upcoming much-cleaner-diesels mandated for both light-duty (Tier 2) and heavy-duty (2007 HD regs).
I don’t share everyone else’s assumption that the latest regs (Tier 2/LEV II) are some “magic bullet” with respect to clean air. They’re very strict WRT NOx emissions, but not strict at all WRT carbon monoxide emissions (CO emission limits have changed virtually none from Tier 1 - http://www.dieselnet.com/standards/us/light.html). The same Tier 1 4.2 grams/mile FUL limit is retained for Tier 2 (down to Bin 5). Yet CO is not only an ozone precursor, there are still areas of the country that are in “serious” non-attainment with the CO NAAQS (http://www.epa.gov/oar/oaqps/greenbk/mapco.html).
Posted by: Carl | 24 August 2006 at 06:26 AM
Shall we refer to this as "The Death of Common Sense"?
I would refer to it as someone stating a lot of things anecdotally without providing any evidence.
Posted by: Joseph Willemssen | 24 August 2006 at 07:58 AM
George, et al, if diesel engines are so bad for air quality, why doesn’t the air quality statistically improve on weekends (yes, I’m bringing up that pesky weekend ozone effect again) when diesel truck traffic has been shown to decrease by as much as 80%
This has already been covered before. First of all, no one has the certain answers. Second of all, if it is caused by some weird effect, it has to do with the pollution dynamics of the current emissions band. Obviously if emissions go towards zero, then there would be nothing triggering pollution. This is common sense.
Posted by: Joseph Willemssen | 24 August 2006 at 08:01 AM
Joseph, there are NATURAL sources of "pollutants" including NOx. You're NEVER going to get to zero.
Posted by: Carl | 24 August 2006 at 08:18 AM
Joseph, there are NATURAL sources of "pollutants" including NOx. You're NEVER going to get to zero.
Did you see the word "TOWARDS" that I used?
Try again, please.
Posted by: Joseph Willemssen | 24 August 2006 at 08:22 AM