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Page added on March 17, 2017

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Diesel may not be running on fumes after all

Diesel may not be running on fumes after all thumbnail

From disdain to redemption to disgrace: Rudolf Diesel’s fuel-frugal invention has travelled a rocky road in North America.

“Slow, noisy and dirty” was the public perception of diesel during its disdain phase decades ago.

Redemption came with the advent of turbo-diesels – such as Volkswagen’s TDI that seduced open-minded buyers with its tsunami of quiet, effortless torque, while new technologies handled the emissions challenge.

Then the disgrace: In September of 2015, Volkswagen was found to have been cheating on U.S. emissions tests.

VW abruptly pulled all its diesels from North America and shows no sign of bringing them back. Since VW was by far the market leader, it seemed diesel’s long journey to acceptance had just hit the ultimate pothole.

However, diesel is recovering from the scandal, says Allen R. Schaeffer, executive director of the Maryland-based Diesel Technology Forum. The number of diesel options from brands other than Volkswagen Group is proliferating.

“Last year was a low point in choice, and the first full year without new products,” Schaeffer says. “Diesel take-rate was its lowest in quite a while. But then it doubled by the end of the year.”

And 2017 is “off to a good start,” he adds.

Two big drivers of diesel’s recovering “take-rate” are the Ram pickup diesel and the new diesel option for General Motors mid-size pickups, he said.

None, however, is more significant than a coming diesel in the 2018 Ford F-150 pickup.

“It’s a very symbolic kind of vehicle,” says Schaeffer. “That such a popular vehicle has a diesel option is a pretty strong statement.”

European luxury brands – including BMW, Mercedes-Benz and Jaguar – offer a variety of diesels while other diesel options coming soon include GM’s Chevrolet Equionox/GMC Terrain CUVs and Mazda’s CX-5.

A simplistic view might be that rivals are rushing to exploit the market space vacated by Volkswagen. The reality is likely more complex.

The automobile development process is a ship that is slow to change course. The diesels coming to market this year were likely under way well before the TDI scandal broke. In turn, auto makers were motivated to develop those diesels by the imperative of evermore-stringent government fuel-economy mandates.

For individuals, diesel’s primary appeal is directly to their pocket-books. Based on official government tests, the VW Passat diesel, for example, could drive 20 per cent further on a litre of fuel than the most economical gasoline version (the diesel advantage used to be greater than that, but gas engines are improving while diesels have become more powerful).

In many jurisdictions, fuel itself is also cheaper, particularly during the warmer months when supply doesn’t compete with demand for heating oil.

In societal terms, a traditional attraction of diesel’s efficiency – back when “peak oil” was the biggest concern – is energy conservation. Now climate change is the bogeyman, and there, diesel’s benefits are more nuanced: The fuel contains more carbon than gasoline, so while diesel does reduce CO2, it’s not quite in proportion with the lowered fuel consumption.

However, CO2 isn’t the only cause of climate change. So is nitrous oxide (N2O, a.k.a. laughing gas), which has a global warming potential 200 to 300 times higher than CO2.

“N2O is present in vehicle exhausts,” says Stelios Pesmajoglou, director of professional programs for the Greenhouse Gas Management Institute, based in Washington, D.C. “Agricultural soil management aside, combustion of liquid fuels in road vehicles is one of the biggest sources of N2O emissions.”

When vehicle emission controls work as they should, the quantities of N2O in vehicle exhaust are tiny compared with CO2 and have about 1.4 per cent of CO2’s global warming potential. But when real-world emissions are up to 40 times higher than the legal limits (as was alleged in VW’s case), then “if this is the case, it is not 1.4 per cent, it is 55 per cent, and this is a serious problem,” says Pesmajoglou.

Never mind the effect on ground-level air quality of the other nitrogen oxides.

The diesel engine used in some Ram and Jeep products has recently also come under suspicion of cheating on emissions tests. Other auto makers insist their new diesels are clean, though some have had their market launches delayed by tightened regulatory oversight by agencies such as the U.S. Environmental Protection Agency.

Which brings us back to the other big imponderable about the long-term future of diesel: U.S. President Donald Trump’s hostility to regulation in general, and his denial of climate change in particular. (His budget proposals call for slashing the EPA’s budget by about a third.)

On the one hand, any relaxation of traditional emissions standards (regulating HC, CO and NOx) could make it easier to engineer and certify diesel engines for the North American market.

On the other, if the Trump administration rolls back fuel-economy/CO2 emissions mandates, auto makers may have less need for diesels to help them comply in the first place. Another unknown: Canada usually adopts the same ever-tighter standards as the United States, but would it do so if the United States went the other way?

In the long term, the discussion could be moot. Saeid Habibi, an electrification researcher at McMaster University in Hamilton, says he can see the case for diesel in heavy trucks, and perhaps in light vehicles for users such as salespeople who travel long distances. Otherwise, “whether [diesel] makes sense for cars I’m not fully convinced. I think the future is more electrification, especially hybrids and battery electric vehicles.”

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11 Comments on "Diesel may not be running on fumes after all"

  1. brough on Fri, 17th Mar 2017 8:08 am 

    Diesel v Spark ignition, the bare facts.
    Diesel are 15 – 20% more efficient than spark ignition engines due to operating at high tempertures and pressures. This means that they require 15 – 20% less hydrocarbon to move the same load over the same distance, with the same savings on CO2 emissions. Down side with HPs and HTs is nitrogen oxides are formed and engine takes longer to reach optimum running temperature emitting unburnt hydrocarbons.
    Answer, use diesel engine vehicles to carry loads over long distances and ban them from densly populated urban areas.

    From a chemistry point of view, nitrogen oxides are more reactive than carbon oxides and therefore less environmentally persistent.

  2. BobInget on Fri, 17th Mar 2017 10:41 am 

    Turned in both our TDI diesels back toVW.
    Today, fuel gets delivered by copper wire.

  3. efarmer on Fri, 17th Mar 2017 12:14 pm 

    Inviting the rockman /rockdoc to chime in. My take is that refineries are designed to crack petroleum into fuels and when built are biased for either more gasoline derivation or more diesel derivation for the life of the refinery. Europe having denser living and more mass transit is biased toward greater diesel yield in refining and America is biased toward more gasoline yield. California drives the US most stringent regs, having a vast population inserted between the coast and the coastal mountains, trapping emissions and making a particulary air quality stringent regulatory case. Tubo diesels suit Europe, electric vehicles suit California, the bulk of the US is a gasoline centric play IMHO.

  4. Anonymous on Fri, 17th Mar 2017 12:56 pm 

    The farticle promotes many so many myths its hard to tell where to start. About the only real relevant point is diesels are more efficient. This is already widely known and its not really news to anyone, or should not be.

    Diesel may be ‘cheaper’ in many justifications but Canada is not one of them. Retail diesel is nearly the same as regular. The price spread is not that great. It used to be a lot better, but uS oil corps charges neearly the same for diesel despite being a lower grade fuel that is not especially difficult to refine. Diesel is also not carried by many stations here any longer. You can find it of course, but its hardly common, many stations simply dont carry it.

    Lastly the idea that diesels are ‘clean’ these days is pure horseshit. Some may be ‘less dirty’ here and there, but the majority are as dirty as ever. In Canada, again, the majority of diesels are heavy equipment, buses etc, most of which, if not all, have few restrictions placed on their emissions. Diesels emissions continue to be big contributors to urban pollution even if the globe and mail tries to claim otherwise.

    Yes, diesels fuel efficiency is real, but that does not make them ‘clean’, or a viable way to move two ton single passenger lumps of metal in endless loops around cities specifically designed to maximize fuel waste and energy.

  5. Sissyfuss on Fri, 17th Mar 2017 1:34 pm 

    To me the salient point is that highly successful global company would resort to such a mammoth scale of subterfuge in order to enlarge its market profile. Corruption such as this is commensurate with a long emergency.

  6. dissident on Fri, 17th Mar 2017 5:16 pm 

    Modern diesel engines use an exhaust particulate filter which removes the only real problem associated with diesels: fine mode carbon aerosol. The diesel NOx issue is an EPA fetish (the one they used to screw over VW). Given a choice of NOx or CO2 the option is trivial. Replacing diesel engines with gasoline ones is insane. Replace them with hybrids or plug-in electrics.

    Mazda has done an interesting modification to the diesel engine by changing the timing of combustion at top-dead-center of the piston stroke. By allowing a longer burn they greatly reduce both the particulate and the NOx emissions. The compression ratio is reduce a lot too. But they still need a particulate filter. Only in North America, thanks the to lawyer mafia at the EPA (look it up, the EPA is staffed by lawyers not scientists or engineers) Mazda will need a small urea NOx treatment system.

    BTW, the diesel efficiency is not 20% or less, it is over 25% and frankly higher in reality given the way IC engines work. Look at the torque number for diesels. It is almost twice as large as for a gasoline engine even if the HP rating of both engines is the same. Torque is what actually drives your wheels and not HP. With the right transmission gear ratios, the torque can be leveraged to save more fuel than the nominal 25% would indicate during acceleration.

  7. Mark on Fri, 17th Mar 2017 7:19 pm 

    How do we stand the HCCI engine which promises diesel efficiency with low emissions?
    Have we made it work yet?
    I think that diesels will always rule heavy industrial uses due to durability and efficiency.
    .

  8. DerHundistlos on Sat, 18th Mar 2017 12:36 am 

    More GREAT news:

    On his first day as America’s new Secretary of the Interior, Ryan Zinke, made the Trump administration’s #1 priority overturning President Obama’s ban on the use of lead ammunition in wildlife refuges.

    Can you imagine how much you must hate yourself to wish death and destruction upon the natural world?

  9. dooma on Sat, 18th Mar 2017 6:10 am 

    DerHundistlos, thanks for the sad information.

    These people are so far removed from nature that probably the only time they ever experience nature is on a golf course or seeing a strange green colour on the ground from their business jet.

  10. rockman on Sat, 18th Mar 2017 3:20 pm 

    farmer – I’m not a refinery guy but will give it a shot. First, I’ll assume you know diesel isn’t “made” per se. But there are different “diesels”:

    Diesel fuel is produced from various sources, the most common being petroleum. Other sources include biomass, animal fat, biogas, natural gas, and coal liquefaction.

    This is rather basic and you already understand much. But for those with no background:

    How Is Diesel Fuel Made From Crude Oil – Diesel fuel is one of the products created from crude oil. During the refining process, the viscous dark thick crude oil is turned into the much lighter diesel fuel. We must first understand what crude oil is and then how petroleum diesel fuel is produced. There are methods to creating diesel fuel other than the traditional method.

    Understanding crude oil – To understand where diesel fuel comes from, an understanding about crude oil is necessary. Crude oil is a naturally occurring liquid that can be refined into various fuels and other petroleum-based products. It is through the process of distillation that crude oil transforms into the different fuels and petroleum-based products.

    At the molecular level, crude oil is made up of various kinds of hydrocarbons (chains of hydrogen and carbon). The hydrocarbon chains in crude oil come in various lengths. Longer hydrocarbon chains have a higher boiling point than those of shorter lengths. Distillation takes advantage of the differences in boiling points to separate the various distillates from crude oil.

    How is petroleum diesel fuel produced – Crude oil refining starts with heating up the viscous liquid to over 400 degrees Celsius. This process turns the liquid into a vapor. The vapor then enters a fractional distillation tower. As the vapor rises, it starts to cool down. The vapor reaches a certain temperature point and the hydrocarbon chains within it return to a liquid state. At different levels of the tower are distillation plates that capture the liquids as they emerge.

    The longest hydrocarbon chains have a boiling point over 400 degrees celsius. As soon as the chains enter the distillation tower, they start turning into liquid again. This emerges as asphalt or bitumen and exits at the bottom. As the vapor rises, shorter hydrocarbon chains begin to liquefy. Fuel oil emerges when the vapor cools down below 370 degrees celsius. This process continues up the tower, with various distillates emerging as the vapor cools further.

    When the vapor reaches between 200 and 350 degrees celsius, diesel fuel begins to emerge. The vapor collects on the distillation plates where it is siphoned off into a diesel holding tank.

    Other methods for creating diesel fuel – The distillation process extracts shorter and shorter hydrocarbon chains as rises in the tower. The shortest chains emerge at the top as a vaporous gas.

    Another option for creating diesel fuel is to recombine some of these shorter hydrocarbon chain distillates. When added together at specific proportions, the hydrocarbons combined create diesel fuel. This creates a diesel fuel that is ready to have required additives blended in and then it is ready for sale.

    So OTOH a certain volume of diesel will be produced from a crude oil whether you want it or not. Which is why there has been a swap dynamic between the US and Europe for decades: we take the gasoline fraction they don’t prefer and we send them some of the diesel fraction we don’t prefer.

  11. rockman on Sat, 18th Mar 2017 3:39 pm 

    DerHundistlos – Do you understand the restriction? It has nothing to do with shooting wildlife on a refuge, right? Wildlife is routinely shot in some such areas. Makes the term “refuge” somewhat contradictory. The reason for the ban was to keep lead pellets out of the environment. Not a terrible idea but not a big deal given not much is consumed by the wild life and lead is essentially non-soluble.

    OTOH shooting birds with steel shot is a bit more inhumane then with lead: much more common to just wound a bird (especially large ones like geese) then a cleaner kill with lead. The bird just flies away and goes off to die slowly. Besides causing unnecessary pain and wasting the meat it allows more birds to be killed since there’s a limit on how many birds you possess and not how many you shoot.

    Personally I gave up hunting geese long ago for that reason: seeing a puff of feathers after the shot and seeing a goose fly away to probably dies slowly in some distant field was a tad depressing.

    Of course this isn’t a pro or anti hunting issue: the govt still allows hunting in some “refuges”. It’s an issue of more humane kills with lead vs steel.

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