Posted on 11/14/2006 2:19:08 PM PST by dennisw
Diesel vehicles now account for nearly half of all new vehicle sales in Europe. In some European countries (such as France), diesel vehicles account for as much as 70 percent of new car sales. Are diesel vehicles a viable alternative to hybrids?
For a 2007 or later model year, diesel passenger car to be sold in all 50 states, it must meet tougher emissions requirements. there is only one T2B5-compliant, 50-state diesel car on the horizon—the new Mercedes E320 BLUETEC to be introduced in late 2006.
Diesels are also known as compression ignition engines, and have a different combustion cycle than gasoline engines. In a gasoline engine, fuel is sprayed into the cylinder, mixed with air, and ignited by a spark from the spark plug.
In a diesel, air is drawn into the cylinder and compressed first without fuel present. This compression heats the air to such a high temperature that when fuel is then injected into the cylinder, it combusts. By using higher compression ratios and higher combustion temperatures, diesels operate more efficiently. As a result, diesel vehicles attain better fuel economy than their gasoline counterparts. This fuel economy advantage is enhanced by the fact that a gallon of diesel fuel contains about 10% more energy than a gallon of gasoline. These two factors help modern direct-injection diesels achieve roughly 50% higher fuel economy than their gasoline counterparts. For example, a European model Honda Accord with a 2.2 liter i-CTDi diesel engine is rated at 43.3 MPG, 49 percent higher than the rating of a Honda Accord with a 2.4 liter gasoline engine. The Camry Hybrid is rated at 39 MPG, 10 percent lower than the diesel Accord.
Modern diesels require something of an environmental tradeoff. While generating fewer greenhouse gas emissions (due to greater fuel efficiency), diesels emit larger amounts of two other pollutants:
Higher emissions of these pollutants are diesels' greatest drawback. There has been an ongoing split in diesel emissions regulations in the US between those required by the Environmental Protection Agency, and those required by the California Air Resources Board.
Currently no new diesel passenger vehicles can be sold in the five states that adhere to the more stringent California requirements: California, Massachusetts, Maine, New York and Vermont. The current diesel Liberty, Beetle, Golf and Jetta, in other words, are 45-state vehicles. The EPA, however, is tightening its diesel emissions requirements, and moving them more into alignment with the California requirements. The point at which the two map exactly for passenger cars is called Tier 2 Bin 5 (T2B5).
For a 2007 or later model year diesel passenger car to be sold in all 50 states, it must meet the T2B5 emissions requirements. Currently, there are no T2B5-compliant, 50-state diesel cars. One is on the horizon—-the new Mercedes E320 BLUETEC, to be introduced in 2007. BLUETEC refers to the emissions after treatment system that enables the vehicle to meet the T2B5 standard. The 2007 E320 BLUETEC has NOx emissions that are more than eight times lower than the outgoing 2006 E320 CDI
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Fuel Economy: 81% of U.S. diesel buyers say they bought a diesel engine for higher fuel economy. U.S. buyers should be aware, however, that in the United States diesel could often be more expensive than unleaded gasoline. (In Europe, diesel is taxed less heavily in Europe, and therefore can be substantially cheaper than gasoline.) |
Availability: Until cleaner fuel and advanced emissions controls arrive here, availability of diesel models will be limited. New diesels are already absent from five states (California, Massachusetts, New York, Vermont, or Maine) that have stricter air quality standards. At the end of 2006, federal pollution rules will tighten, pushing cleaner diesel models out of the entire U.S. market. |
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Longevity: Diesel engines tend to last longer than gasoline engines, leading to higher resale values for many diesel-equipped models. |
Emissions: Particulate and NOx emissions are higher than those of comparable gasoline vehicles. (Most diesel engines can use biodiesel without any modification.) |
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Power: Diesels provide greater torque, which can be important for drivers who carry heavy loads or tow trailers. |
Price: Adding a diesel engine to a Volkswagen Jetta adds over $1000 to the car’s price, and in medium-duty pickups the increased cost of a diesel engine can exceed $5000. |
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Incentives: Future clean diesels will be eligible for the same types of tax benefits that hybrid vehicles receive. Buyers of the Mercedes E320 BLUETEC, for example, qualify for $1500 off of their tax bill. |
Availability of Fuel: Diesel owners must also cope with a refueling network that is more limited than that of gasoline, although their vehicles’ longer range means they have more time to find a station that sells diesel. |
It's technically possible to use a hybrid drivetrain with a diesel engine. In fact, PSA Peugeot Citroën recently showed a diesel-hybrid prototype: the 307 CC Hybride HDi, a compact convertible that gets 70 miles per gallon, about 30 percent better fuel economy than the existing diesel version. No one makes diesel hybrids yet, mainly because they are expensive. The added benefits come at a double expense—more for the hybrid system and more for the diesel engine. PSA Peugeot Citroën may introduce a diesel hybrid to the market as early as 2010. But no promises yet from the company.
ping
Another benefit from the recent plunge in US gas prices is that we have been spared from additional fart fan, ethanol and alternative energy articles.
What I still don't understand is why is diesel MORE than gas now when its a byproduct of gasoline production. Its one of the first steps so they don't have to do nearly as much production as gas.
In the not-too-distant future, diesel engines will rule the roads and skies.
It's driven by marketing. Diesel has more BTU than gasoline, so they now charge more. Surprised it took this long.
"Diesel vehicles now account for nearly half of all new vehicle sales in Europe. In some European countries (such as France), diesel vehicles account for as much as 70 percent of new car sales."
Is Europe, especially France, a roll model to follow?
Hybrids, electrics and diesels are all dancing around the problem without doing anything to solve it. Keep working on the efficiency of gasoline engines (as companies like Honda do) while developing the fuel cell and its necessary infastructure.
How come THEIR environmental lobby didn't block THEIR nuc plants and diesel particulate matter?
I had a diesel Rabbit. It was a great car. I'd love to get another diesel. But I sure as hell don't want to pay for a Mercedes. I like my cars sweet and simple.
This is just another instance of how environmental protection laws can backfire. Diesels are much cleaner than they used to be, but they set the bar so high that it can't be reached--probably deliberately, doing some of their industry donors a favor.
Diesel's demand is pretty much constant throughout the year, hence the price usually isn't as volitile as gasoline's.
Diesel and Heating Oil are basically the same stuff, so in the winter when the demand for heating oil increases, the price of Diesel also rises.
it's not necessarily the cost that determines price - the balance of supply and demand would affect price. Which makes me wonder - what happens when the demand for gasoline drops well below the demand for diesel? Can diesel be made as cost-effectively when it's no longer a by-product?
It isn't a by-product, and second, you don't understand the market for distillate, the base stock for diesel fuel.
On the futures markets, you see crude, gasoline and "distillate" futures, but no "diesel" futures. Why?
Well, here are all the things made from "distillate" stocks:
1. Diesel, both #1 and #2 for on-road use.
2. Diesel, both #2 and #1 for off-road use.
3. Jet-A.
4. JP-5, JP-8.
5. #2 home heating oil.
Right now, diesel prices are suffering from:
a) speculation that there will be a cold winter, so home heating oil consumption is presumed to go up during this time.
b) Commercial air traffic is picking up again, and air carriers are seeing the recent dip in jet fuel prices as an opportunity to hedge against a large upswing in the next two years' price of jet-a.
c) the economy is actually hummin' right along. Diesel is in short refining supply here in the US, especially since the mandated change-over to ultra-low sulphur diesel. Some of the smaller diesel refining operations aren't able to make ULSD, and they're now going to be supplying their product to the last market for higher-sulphur diesel: offroad uses, typically farms and construction.
The diesel fuel market is affected much more by the industrial base economy than gasoline prices are. Gasoline prices can drop as soon as consumers change their behavior -- drive less, or buy more efficient cars. The diesel market -- most of us don't have a choice. Products have to be hauled, crops have to be harvested, we have to use diesel and we don't have much discretion in the matter.
Great information. THANKS!!
In Northern Calif., diesel is around 40 cents more per gallon than regular. $2.30 gas - $2.70 diesel = @ 18%.
Otto-cycle gasoline engines aren't going to see substantial increases in their efficiency from where they are now due to the "knock limit" -- ie, to decrease their specific fuel consumption, they need to increase the compression ratio. The only way to increase the compression ratio without pre-combustion "knocking" would be one or more of:
1. Increasing the octane of the fuel.
2. Water injection.
3. Ethanol injection.
4. A whole new type of engine, heretofore not known.
#1 isn't going to happen. #4 would be hugely expensive for any automaker.
So that leaves #2 or #3.
Gasoline was a byproduct when simple distillation was used to refine products. You distilled out only what was in the crude.
Today they use cracking to refine the crude. Refineries adjust production of diesel (& heating oil) or gasoline depending on the seasons & markets..
In the meantime, the alternative to Japanese small cars w/ diesels is the KOREANS. Always on the lookout for markets ignored by Japan, they have taken diesel design to heart and are probably ahead of Japan in passenger vehicle diesels - Hyundai/Kia have a great 1500cc CRDI diesel that is cheap and good... interestingly enough I believe the French have a stake in Kia so perhaps there is where the interest in diesels stems from...
The air is clean enough, already! We need reduced dependence on foreign oil
Replying to the original article:
Yes, absolutely. Before I got into the farming gig, I used to be an engineer, as in "fur years ago, I cudn't evin spel 'injuneer' -- today I are one!" - a EE to be specific. I completely agree that diesels are a faster, cheaper, more durable way to raise the US fleet fuel efficiency than these silly hybrids. Want to see really high mileage cars? Get rid of the gasoline engines used in hybrids and put in a small diesel engine, running at a constant 1700 RPM, only when needed. The conversion of mechanical to electrical energy, only to be converted back to mechanical energy again is a distraction. The way hybrids are gaining their efficiency is to smooth out the load on the engine in stop-n-go traffic. Take a hybrid out onto an open road and suddenly, you notice it isn't quite so fuel-economical as you'd hoped.
Take a modern diesel out onto the open road, set the cruise control and enjoy 40 MPG (and more!) in peace and quiet, without all the goofy battery/motor/computer lash-up of a hybrid. VW delivers this efficiency today.
Diesels have ALWAYS been a viable way to raise the fleet mileage of the US. Sadly, the US consumer has had a reluctance to acceptance of diesels in their cars, because of the following:
1. CARB, the California Air Resources Board, has a jihad on against diesel engines. Every time diesel engine manufactures meet or exceed CARB's latest specs, CARB raises the bar yet again, which results in what you see today -- cars that have diesels being "45-state compliant." The cars cannot be sold in California or any of the other four states stupid enough to copy California's emissions standards.
BTW -- the CARB propaganda about diesel emissions are notoriously rooted in the past. Modern diesels are now substantially cleaner than they were even 10 years ago, and CARB continues to distribute the idea that diesels are disproportionately responsible for air pollution in Califonia. CARB has pushed the issue to a point where researchers are now noting a "weekend effect" in smog in CA, where the speculation is that because there is actually too little (insert irony here) NOx in the air on weekends, the level of smog-producing ozone is higher on weekends.
2. GM's absolutely crap-infested diesels in their cars in the late 70's. GM took a gasoline 350 V-8 block, put in different pistons and heads on it and called it a "diesel." The same thing was done with the VW Rabbit diesel, aka "The Turtle."
Anyone who has been around diesels knows that for the vast majority of successful diesel engines, you simply cannot just take a gasoline block, insert diesel components and create a successful diesel. It simply won't work. Diesels have to be built to withstand the torque, heat, compression, etc -- all at levels gasoline engines can't even dream of until you reach race-level performance.
You can, however, retrofit a diesel engine block and create a massive gasoline engine that will last for centuries.
Even into the 90's, GMs 6.2L and 6.5L diesels in their pickups were largely crap. The Cummins B5.9 and IH/Navistar 7.3L engines in the Dodge and Ford pickups (respectively) were real diesel engines that gained very solid track records for performance and longevity. That's why until GM went and co-operated with Isuzu to build a new diesel for their pickup line, Ford and Dodge owned the lion's share of the diesel pickup market.
3. Too many people associate diesel engines with the soot-spewing Detroit two-stroke engines in muni bus fleets. Everyone at one time or another has been hehind one of these beasts on a city street and wondered "What the hell are they burning in there? Soft coal?!" and the reputation of diesels was that of "Uh, we don't want one of those in the family car, no way, no how."
The diesel auto manufactures have to break this mental image of US consumers. The Detroit two-stroke diesel engines were used in some applications like this because they were a way of getting lots of HP into a small, compact engine. They're not used any more in new trucks or buses. The two-stroke is an antique in diesel engine evolution. They had their place and time and it isn't here or now.
4. The absolute stupidity of GM, Ford and Toyota(!) to not import their successful small diesel engines into their US product lines. Toyota has a line of small pickups and utility vehicles in Oz and the Pac-rim with absolutely wonderful small diesels in them. Simple to maintain, gutsy, nearly indestructable 2.2L diesels in their Hi-Lux and SR-5 pickup line. Finding one of the diesel engines in North American is nearly impossible. Automakers keep pointing to the customer response of the late 70's and saying "The US consumer doesn't want diesels." Hogwash. The US consumer doesn't want to be ripped off, and that's what the GM/VW efforts of the late 70's did: rip off the consumer.
Modern diesels with computer-controlled, very high injection pressure fuel systems are cleaner, quieter, more efficient, easier to start in the winter, etc, than the previous diesels. They bear little similarity in operation to the classic soot-spewing diesel of the 70's. I can hop in my F-350, get it warmed up and then romp on the throttle and break the rear tires loose in the first three gears at will - and emit no black smoke. While it is a tad slower than a gas-engine pickup from 0-30, once I get the turbo spooled up and get "on top of the torque curve" (ie, get the engine above 1700 RPM), I can pass any passenger car in sight. The typical passenger car will pass me off the line to about 40 MPH. After that, I just mash my foot into the throttle, spin the turbo up and I go from 40 to 90 with no apparent effort whatever. Most cars' gasoline engines, however, run out of torque at higher RPM's, so their ability to accelerate at higher speeds depends on having a very high-ratio tranny to get the engine RPM's back down again -- which most cars won't have above 60 MPH.
Horsepower sounds impressive to the auto consumer. What most auto consumers don't know is that HP is useless without torque. Torque is what makes your car go up hills or accelerate. And here in Nevada, we have lots of mountains to climb over. Empty to 1,500 lbs of load, I can go over any mountain range I care to in overdrive, passing most all high-end passenger cars with ease at 70+ MPH. You can't do that with a gas engine pickup. I can pull up to 7 ton loads on trailers behind me. When I do, I get 12 MPG. A F-350 with the V-10 gas engine gets, oh, 6 to 7 MPG. Empty, I get 20 MPG and the gassers get maybe 14 to 15 MPG.
There's no way I'd own a gas engine in a pickup to do farm work anymore. If VW still sold the Passat TDI station wagon, I'm pretty sure we'd buy one this next year. Sadly, because of California's emissions, VW doesn't want to offer a 45-state car, so the rest of us are deprived of 45+ MPG cars for the sake of California environmental dogma.
I just got back from a trip to Spain, during which I rented a Peugot Diesel station wagon. It was pretty small by US standards -- I couldn't imagine my two big Labs in the back -- but it handled two big suitcases behind the back seat. It was a nice little car, fairly basic, but handled well and was sufficiently peppy, even on mountain roads. Very good fuel efficiency -- Madrid to Toledo to Granda to Cadiz to Malaga on less than a tank and a half of fuel. It would be a good choice for a young family or for city dwellers who want a little more room than the average sedan supplies.
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