could compete fairly at the pump. But another hurdle still is the
relative lack of filling stations across the U.S. with diesel
pumps.)
Diesel car proponents would like to see the fuel taxation field
leveled - so that gasoline and diesel (which is currently taxed higher)
could compete fairly at the pump. But another hurdle still is the
relative lack of filling stations across the U.S. with diesel
pumps.
Image: cafemama, courtesy Flickr.
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Dear EarthTalk: I don’t understand why there are many European diesel cars with very high mileage ratings that are not available in the U.S. Can you enlighten?
-- John Healy, Fairfield, CT
Different countries do have differing standards in regard to how much pollution gasoline and diesel automobile engines are allowed to emit, but the reason you see so fewer diesel cars in the U.S. is more of a choice by automakers than the product of a decree by regulators on either side of the Atlantic.
Since the advent of the automobile age in the U.S., gasoline has been king of the road; today upwards of 95 percent of passenger cars and light trucks on American roads are gas-powered. And the federal government has done its part to keep it that way, taxing diesel at a rate about 25 percent higher than gasoline. A recent assessment by the American Petroleum Institute, an oil industry trade group, found that federal taxes accounted for 24.4 cents per gallon of diesel but only 18.4 cents per gallon of gasoline.
In Europe, where in many regions about half of the cars on the road run on diesel, these tax incentives are flip-flopped, with diesel drivers reaping the economic benefits accordingly.
But according to Jonathan Welsh, who writes the “Me and My Car” Q&A column for The Wall Street Journal, interest in diesels—which typically offer better fuel efficiency than gas-powered cars—has gained significant momentum in the U.S. in recent years given the uptick in gasoline prices. The popularity of diesels also surged, albeit briefly, in the mid-1970s after the U.S. suffered its first “oil shock” that sent gas prices through the roof. But gas prices settled down and so did American fervor for diesels at that point.
Today, though, with so much emphasis on going green, diesel cars—some of which boast similar fuel efficiency numbers as hybrids—are on the comeback trail in the U.S. Recently passed regulations require diesel fuel sold in the U.S. today to have ultra low emissions, which appeals to those concerned about their carbon footprints and other environmental impacts. Also, the increased availability of carbon-neutral biodiesel—a form of diesel fuel made from agricultural wastes that can be used in place of regular diesel fuel without any engine modifications—is convincing a whole new generation of American drivers to consider diesel-powered cars. Right now only Volkswagen, Mercedes and Jeep sell diesel-powered cars in the U.S., but Ford, Nissan and others plan to launch American versions of diesel models already successful in Europe within the next year.
Meanwhile, the U.S. Coalition for Advanced Diesel Cars, a trade group that represents several automakers as well as parts and fuel suppliers, would like to see the U.S. government increase incentives for American drivers to choose diesel-powered engines by leveling the fuel taxation field—so gasoline and diesel could be competing fairly at the pump—and by boosting tax breaks on the purchase of new, more fuel efficient diesel vehicles. One hurdle is the relative lack of filling stations across the U.S. with diesel pumps, but as such vehicles become more popular, filling stations that don’t already offer them can relatively easily add a diesel pump or two.
CONTACTS: American Petroleum Institute, www.api.org; U.S. Coalition for Advanced Diesel Cars, www.cleandieseldelivers.com.
EarthTalk is produced by E/The Environmental Magazine. SEND YOUR ENVIRONMENTAL QUESTIONS TO: EarthTalk, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php. EarthTalk is now a book! Details and ordering information at: www.emagazine.com/earthtalkbook.
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26 Comments
Add CommentLets not forget that there is not a car in the world that will meet California's upcoming Diesel regulations and that most of the existing high mileage diesel cars in Europe don't meet California's present pollution regulations. It' sogvernement regualtiosn not the auto manufactures.
Reply | Report Abuse | Link to thisyes that is how things get changed, do you think that the auto companies will willingly make their cars more fuel efficient? of course not, there's too much money to be made by oil companies. Fuel efficiency standards haven't changed since Jimmy Carter, why? Big Oil Lobbying.
Reply | Report Abuse | Link to thisI cannot understand for the life of me why anyone thinks diesels are a good idea. I live in the UK, these dirty engines are increasingly plentiful on our roads and I can tell you that even the newest ones stink and belch out visible filthy black particulate emission when the driver puts their foot down (Google PM10 for why this is bad). It would seem to me to be stupid (nothing new from our government) to risk trading our health for the sake of a small, likely insignificant improvement in CO2 emissions.
Reply | Report Abuse | Link to thisI think if you're in the states you should be glad you don't have very many of them.
Five states banned the sale of new diesel cars because they pollute too much. They do not get mileage similar to comparable hybrids, although better than regular gasoline cars. Almost all biodiesel you buy is made from food crops, which is worse for global warming that regular diesel. Good luck finding a source from waste. They have also been a huge source of soot in Europe, the second leading cause of global warming.
Reply | Report Abuse | Link to thisThe high efficiency of the diesel is its 18:1 expansion ratio which is also its compression ratio. This means that the peak pressure is extremely high therefore its structure is massive.
Reply | Report Abuse | Link to thisThe spark plug is a pretty primitive device; just a bit of ceramic and a few wires.
The diesel injector and fuel pumps are extremely high precision items that have to be assembled with tweezers. The heat of the hands will expand the components so they jam.
Therefore diesels are expensive to build and maintain.
The wide use of diesels in Europe was that diesel was that diesel was about half the price of petrol(gasolene).
Now, in Australia, diesel has become more expensive than petrol.
Tassie: diesels don't have spark plugs. They ignite the fuel via compression. What you're probably thinking of are glow plugs, which are used to heat up the cylinders in cold conditions. They're completely unneeded in warmer weather (I know because I went a whole summer with the entire glowplug circuit gone in 7.2L diesel van engine).
Reply | Report Abuse | Link to thisshufflingB: just because you can see the diesel exhaust when someone floors it doesn't make it any worse than the invisible emissions that come out when you do same with a gasoline car. It's just a case of 'out of sight, out of mind.' Most soot comes from large trucks which often don't have costly exhaust scrubbers on them.
Biodiversivist: the 2009 VW Jetta TDI gets better highway mileage than the 2007 Prius (52mpg and 51mpg respectively); impressive for what is essentially a full-size sedan. With ultra-low-sulfur diesel, the particulate emissions are less too. The latest Prius tops that mpg number for City mileage, but the UK TDI version of the Ford Focus gets 62mpg, better than the Prius even in city driving (where the Prius is at its most efficient).
I think some people are a little unclear on the most recent batch of 'clean' diesels, versus older ones (the advances really are that new), as well as the difference between LEV and ULEV, and again the difference between regular diesel, low-sulfur diesel, and ultra-low-sulfur diesel. Putting regular diesel in one of these new clean diesels will still be stinky at sooty.
To kllrbny.
Reply | Report Abuse | Link to thisThe point I was making is that spark plugs are cheap and nasty. Diesels don't use them. Instead they use very high precision fuel pumps and injectors, which are very expensive.
In the early eighties the company that I worked for had two mechanical inspectors who spent all their time on the road visiting subcontractors. Someone in head office decided that a diesel powered car would save money on fuel and it did.
Then they got the bill for the first service!! As I said, diesel injectors are many times more expensive than spark plugs.
Also these cars were built with components designed for petrol engines one vehicle had a new engine under warranty the original engine wore out in under 40,000 kilometres.
In real world driving conditions the new diesel engines far exceed hybrids. Fast acceleration and true highway speeds greatly reduce mileage of hybrids. The new high pressure injection diesels are relatively clean. The addition of low sulphur fuel and upcoming catalytic converter technology make diesel the way to go. If you want a car with some decent performance and fuel efficiency I would highly reccomend the new diesels. I have had one for two years and I am a very satisfied customer.
Reply | Report Abuse | Link to thisHere in Europe, Diesel fuel used to have a lower taxation than gasoline, the current situation is that both Diesel and Gasoline receive the same taxes, thus making an equal or slightly higher price for Diesel fuel, but a very important advantage remains in that Diesel engines use less fuel, they are more efficient by the kind of thermodinamyc cycle they use, and last longer, although failures are a bit more expensive to fix
Reply | Report Abuse | Link to thisDiesel engines were promoted by car companies because they are more expensive, thus increasing the profit margins. They are only efficient when they reach their full operating temperature, which seldom occurs for most people going to work or shopping. They sold because diesel was taxed less, and people thought that with increased mileage over its lifetime it would end up saving money. Europe refines so much diesel that excess gasoline has to be shipped to the US.
Reply | Report Abuse | Link to thisThey stink, even the brand new "clean" diesel. They are really noisy too (low frequency but high energy noise) finally vibrations affect driving comfort.
Reply | Report Abuse | Link to thisDiesel engines last longer and use less fuel tah petrol counterparts, as Diesel cycle is inherently more efficacious. In Europe Diesel fuel got lower taxation than gasoline, but now, taxes are equal for both Diesel and petrol, and pump costs are equal or slightly higher for Diesel. The main problem in Diesel engines are particulates emissions, a problem neglected some years ago, but currently well solved
Reply | Report Abuse | Link to thisI have been passenger on a Diesel in Europe, I felt no real difference from a gasoline car, on the other hand, the person driving it said it was somewhat sluggish (slower acceleration and reaction), perhaps because Diesel engines are running on a lower RPM regime than gasoline ones, it is true, the engine also sounds different, kind of a clicking sound rather than the humming of a gasoline engine, but not so noisy as to be intruding.
Reply | Report Abuse | Link to thisAll in all, I'll buy a diesel as soon as I find one that fits my needs here in Mexico
For a more detailed evaluation of diesel passenger cars and the environment:
Reply | Report Abuse | Link to thishttp://www.ucsusa.org/assets/documents/clean_vehicles/diesel-123.pdf
Half my driving career Ive been driving diesels, first an old 300d Mercedes and now a Jetta TDI. I will swear by the engine type, and the fact I have a biodiesel provider who refines used cooking oils and agricultural byproduct (cotton oil). The longevity of diesel engines is unparalleled (400,000 miles on the 300d), but the new technology to give it kick (turbo chargers, etc) can be temperamental. My next car will be diesel or electric (or both, see VW hybrid). I would very much like a domestic, as the German and Japanese are expensive to maintain.
Reply | Report Abuse | Link to thisHalf my driving career I’ve been driving diesels, first an old 300d Mercedes and now a Jetta TDI. I will swear by the engine type, and the fact I have a biodiesel provider who refines used cooking oils and agricultural byproduct (cotton oil). The longevity of diesel engines is unparalleled (400,000 miles on the 300d), but the new technology to give it kick (turbo chargers, etc) can be temperamental. My next car will be diesel or electric (or both, see VW hybrid). I would very much like a domestic, as the German and Japanese are expensive to maintain.
Reply | Report Abuse | Link to thisI think diesels are our best bridge until fuel cell, technology is perfected, hybrids have emissions advantages but are not cost effective (not yet at least), plug-ins charged from electricity from coal plants is not green at all ( and we have a lot of those in the US) the CO emissions from diesels are not just marginally better than gasoline are significantly better. 35-45% more efficient, and with 1.2 1.6l diesels is not hard to get 55mpg+, extremely reliable, one up front cost (no battery replacements every 5-6y)
Reply | Report Abuse | Link to thissB: "I live in the UK, these dirty engines are increasingly plentiful on our roads and I can tell you that even the newest ones stink and belch out visible filthy black particulate emission when the driver puts their foot down (Google PM10 for why this is bad). "
Reply | Report Abuse | Link to thisI live in France where more than half of road vehicles (and all trucks) are powered by diesel. I see nothing of the kind, and unless one was right next to the car, one would not be able to tell the difference in noise level.
Perhaps that is due to the fact that there are obligatory car inspections in France, which verify exhaust emissions -- and a car with too high an emission level will go without its certification until the diesel motor is attended to?
Eco-steve, you have no idea what you are talking about. I have spent the last 15 years moving back and forth between the states and Europe every three years. I always buy an inexpensive second hand diesel for the European tours. I consistently get better than 40mpg cumulative daily driving, and I have never required an engine related service other than oil changes. My current vehicle has 186,000 miles (not Km) on it and goes like a champ. The diesels in the states in the 70s sucked because they were GM gas V8s that they just slapped diesel heads on. Typical deplorable Detroit big three workmanship. If you buy a Japanese, or German diesel you can't kill it with a nuke.
Reply | Report Abuse | Link to this{They do not get mileage similar to comparable hybrids, although better than regular gasoline cars.}
Reply | Report Abuse | Link to thisNeither do they cost as much as a hybrid.
As for the pollution, they meet European standards, which are far more severe than those in the US.
It appears hybrid cars provide environmental benefit, it actually does not. To understand this point, one has to know where are the electricity that charges hybid cars coming from? In other words, hybrid cars only transfer the generation of pollutions from cars to power plants. Only when cars use high efficient engines, e.g., diesel engines, then it is friendly to the environments. Would you please comment on this statement?
Reply | Report Abuse | Link to thisdiesels are not dirty in the slightest. if everyone in the world drove the new current clean diesels of the decade our environment, engergy consumption, and wallets would have a much needed improvement. diesels should be in everything. Diesel for life
Reply | Report Abuse | Link to thishybrids are junk. a tdi will smoke a hybrid on a gallon of fuel. over in europe there getting close to 70 miles to the gallon with there turbo diesel passenger cars. 24 of the 25 most fuel efficient cars in the world
Reply | Report Abuse | Link to thisare diesel.
hybrids are junk. a tdi will smoke a hybrid on a gallon of fuel. over in europe there getting close to 70 miles to the gallon with there turbo diesel passenger cars. 24 of the 25 most fuel efficient cars in the world
Reply | Report Abuse | Link to thisare diesel.
Although many people think that because diesels are dirty, expensive and that its slightly more expensive in some countries (talking pennies) its a good reason not to buy one. Spanish automobile production company SEAT produce a good looking small hatchback that it capable of reaching an amazing 95Mpg on the highway. The 1.6 diesel ford focus (european) is cable of 75Mpg on the highway. But, its not only diesel that has become efficient, many european gas engines are very economical with the 2.0 liter euro ford focus hitting 52mpg compared to the max 24 that the us 2 liter can hit and we are still talking about a car that hits 130mph tops and 0-60 in 9 seconds. The US is lacking far behind the rest of the world in engine technology.
Reply | Report Abuse | Link to thisOK, lets debunk some of the myths, that America clearly believes about diesel cars. Please bear in mind, that I run a Diesel car and have done so for nearly 9 years and 115,000miles now. I am also a fully qualified mechanic.
Reply | Report Abuse | Link to this1) American consumers believe that diesel is dirty.
Diesel engines did used to be dirty. Modern new generation 2nd and 3rd generation common rail turbo diesels emit less Co2 and less overall emmissions than a comparable petrol engine. Poorly maintained diesels will also still emit soot etc, but thats not the engine's fault, its the users fault. A poorly maintained pterol will polute just as badly, its simply that you cant see the polution.
2) Diesels don't do any better MPG than a hybrid?
Hybrids only offer real and significant fuel economy gains over a non hybrid in stop start driving, where the energy recovered by slowing, is used to charge the batteries/capacitors within the hybrid system, and re-uses the energy used to accelrate the car in the first place. On an open road (what the US terms highway) a hybrid gains little benefit from its hybrid system, because your not slowing down to recharge the system, but you are carrying around a heck of a lot of extra weight, in motors, batteries and electronics etc. Offical fuel consumption tests, in both the US and Europe are done under specific test circumstances that favour hybrids, because they are always stop start and always done at low speed. My 9 year old diesel Ford Focus, averages 45mpg at 90mph... could a prius match that? Not in a million years.
3) Diesels are expensive to maintain.
Diesels have far less normally serviced parts than a petrol engine. in a normal diesel engine service, the only things changed are the engine oil, the oil filter, fuel filter and air filter. With at least 12000 mile service intervals, they are cheaper to service than a petrol which has expensive spark plugs to replace. Diesels dont have spark plugs btw. Diesel injectors are expensive to make, but will generally last the life of the engine, if not at least 100k miles. Diesel itself is a lubricant, coupled with lower average rpm, and stonger mechanicals (to cope with the much higher compression in the engine) diesel engines will on average do far more miles before needing a re-build than a petrol.
The reality is that because gas prices in the US have been so low, your cars even now are inefficient, because its not worth making them better. If you want to know how good diesel can be, look up the BMW335d or 535d. 40mpg, nearly 300hp, artificially limited to 155mph max.