Diesels may turn the heat up on hybrids
While hybrids are still a hot topic here in the U.S., especially after Toyota just introduced the new Camry Hybrid at the Detroit auto show, diesels appear to be making a strong move to capture the North American mileage crown. We base this claim solely on the passion with which Dieter Zetsche talked about DaimlerChrysler’s new BLUETEC 3.2L engine that will be fitted into everything from the E-Class sedan, R-Class tourer, ML-Class SUV and new GL-Class full size SUV.
Zetsche stressed two things over and over in his press conference on the BLUETEC 3.2L diesel engine: 1. It meets the world’s most stringent exhaust emissions standards, including all 50 U.S. states, and 2. it gets great gas mileage in every vehicle.
The best matchup between diesels and hybrids we saw at the Detroit auto show were GM’s new Two-Mode Hybrid Tahoe and the Mercedes Benz GL 320 BLUETEC, two large and heavy SUVs that could stand a little moderation in their liquid diets. Where Zetsche was shouting from the rafters that the BLUETEC-equipped GL-Class would get 26 mpg, GM would not speak about what actual mileage its Hybrid Tahoe would return.
Instead, every press release says the H-Tahoe will see a “25 percent improvement in composite fuel efficiency” over the standard Vortec V8. We did the math and that would turn out to be 20 city/25 hwy, or a combined average of 23.5 mpg. Nowhere does GM mention composite power numbers for the Two-Mode Hybrid system, either. The BLUETEC 3.2L diesel six, however, produces 224 hp and an undisclosed but presumably large amount of torque.
Reader Comments (Page 1 of 3)
Moveon 2:07PM (1/17/2007)
It always baffles me how people forget that diesel fuel contains 20% more oil than gasoline. In essence, that means that you have to deduct 20% from the diesel mileage when comparing them to the gasoline hybrids. Taking this fact into consideration, diesel engines are only about 15% more efficient than conventional gasoline engines, hybrids, on the other hand, are 40% more efficient.
Diesel engines are great towing machines because the maximum torque is in the low revs. At highway speeds, they are still more sluggish than gasoline engines. Hybrids combine the low rev torque of the electric engine with the high rev torque of the gasoline engine: this leads to a much more powerful overall performance for a passenger car. Hybrids are still much more quiet and comfortable than diesels.
Even though these newer diesel engines are much cleaner than they used to be, they don't even get close to the low emissions of the hybrids.
One last word on bio diesel: biodiesel causes higher Nox emissions than fossil diesel. It generally stinks terribly, has to be mixed with fossil diesel, and takes a lot of (fossil) energy to be produced. The world consumes about 250 years of the annual global agricultural production in fossil fuels; I don't think that you can ever make a dent in the global fuel consumption with bio diesel.
Obviously, this was written by a hybrid owner. Move on people, diesel is the last century's technology, no matter how you package it. Hybrids are the bridge to the fuel cell cars of the 21st century.
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Lorna Taylor 9:06AM (2/05/2007)
Am transitioning into a greener vehicle. Love the Mercedes 320E Bluetech but concerned by the fact that the 2007 cannot be sold in all 50 states due to emmission standards. Not sure if this is not a big deal, or, if I should wait a year or two until the BlueTech is true blue. I am also considering simply moving forawrd now with a Prius. (Am not a Lexus fan so not interested in their hybrids.) I am interested in any comments or thoughts regarding the comparison between 2007 Mercedes Bluetech versus Toyota Prius emmissions. Thanks.
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tony belligerent 1:27PM (1/12/2006)
Please please please let this engine bleed into other DCX cars. Bluetech Dakota, Bluetech Caliber (duh?).
More power, more MPG?
Common sense.
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Jim in Tampa 1:32PM (1/12/2006)
"Zetsche stressed two things over and over in his press conference on the BLUETEC 3.2L diesel engine: 1. It . . . and 2. it gets great gas mileage in every vehicle."
It should be fuel mileage, not gas mileage. Diesels don't run on gas.
I'll take a Mercedes E320 with a Bluetec diesel over a Prius anyday!
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Robert Brodrecht 1:32PM (1/12/2006)
In California, diesel is usually 20 cents more expensive than premium (91 octane) gasoline. Premium is usually 20 cents more expensive than regular gasoline.
I did some (perhaps flawed) math.
Assumptions: The diesel SUV gets 26 MPG at $3.00 per gallon (which is what it was last time I looked). The hybrid SUV gets a combined 23 MPG at 2.60 (40 cents cheaper, as per above... I don't know what the going rate was when diesel was $3, as my car uses premium).
If the cars go 100 miles, the diesel costs $11.52 to operate (100 miles / 26 miles per gallon * $3). The hybrid costs $11.28 (100 miles / 23 miles per gallon * $2.60). For 200 miles, the results were diesel, $23.07, hybrid $22.59.
Don't crucify me if I screwed up the math. Thnx.
I'd like to see figures for more aerodynamic cars, though.
I think there is a perception problem, as plenty of people do, with cost-at-the-pump and cost-at-the-dealer. A good diesel would be nice because there are fewer components to worry about and the battery debate is not an issue (so they should be cheaper to make and maintain). But, if your concern is the environment, it's hard to beat a hybrid with any other mass produced, available vehicle.
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Viggo 1:34PM (1/12/2006)
The displacement is acutally not 3.2liter but 2987cc, despite the x320-name.
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goat 1:48PM (1/12/2006)
I'd like the 4.2 V-8 CDI (with two turbos) in a Challenger, please.
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M1EK 1:56PM (1/12/2006)
Applying the reality deflator (currently, people claim diesels get mileage just as good as hybrids when they clearly do not - see
http://mdahmus.thebaba.com/blog/archives/000247.html
, we could assume that MAYBE with this newfangled diesel, they might just catch up.
At that point, and again, this is an optimistic reading, you still have to deal with the more expensive fuel, and with the extra pollution (and no, meeting 50-states exhaust rules doesn't even bring it within shouting distance of the emissions of the dirtiest hybrids out there - the hybrids are far exceeding those requirements today).
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voiceofreason 2:08PM (1/12/2006)
#3, Robert
Good observation, but I believe California's diesel prices are so high because of extra environmental taxes, which is in turn because diesel engines are (were) assumed to be dirtier. (Can someone confirm, please?) In other states, where diesel does not ask for such a premium price, one could potentially save money.
What is the technology that makes these diesels so much cleaner? Details, please, Autoblog?
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M1EK 2:25PM (1/12/2006)
Diesel is more expensive pretty much everywhere, and has been for quite a while. Had nothing to do with taxes and everything to do with refining issues.
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Peter 2:34PM (1/12/2006)
I love the idea of clean diesel but is a system requiring you to fill up a Urea/Amonia tank along with fuel really going to fly?
If you go to the mercedes bluetec page you get a description how the system works. It requires a dual fill up. A tank of "Addblue" that is used at a rate of 25Liters diesel/1 liter Addblue.
http://www4.mercedes-benz.com/specials/scr/en/index_nocom_en.htm
You need a infratstucture to support this. And how many people will just stop filling up the "addblue" tank. The engine will actually run dirtier than the average diesel without Addblue, because they rely exclusively on "addblue" for Nox emission reductions.
You also need ULSD fuel. ~2007 for USLD but at what cost.
So how much will ULSD and Addblue fillup cost? Will people actually keep the Addblue filled up even if available at every service station?
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Dustin in Cal 2:40PM (1/12/2006)
I find it interesting that there are no parallel diesel hybrids. A diesel hybrid Prius would probably average 70 to 80 mpg or more with a similar displacement TDi motor from VW (only comparison I know of).
Many people complain that diesel is not as eco-friendly as gas electric, but I say these folks are looking at the wrong end of things. Once gas is used it is gone forever, and therefor is a wasteful technology for the planet. Bio-diesel can be regrown at will, and is only marginally more polluting in a modern diesel motor such as a CDi (from DCX) or a TDi (from VW)
Food for thought, or to power your car.
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Peter W. 3:01PM (1/12/2006)
Couldn't BLUETEC owners just pee in the addblue tank?
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Steve kennedy 3:07PM (1/12/2006)
To voiceofreason: The big advances in cleaning diesel emissions comes from several areas: better fuel management(injection), cleaner fuel and catalytics.
Diesels start with higher compression ratios which, when combined with better fuel and better fuel management, means a more complete burn of the fuel charge. That means lower emissions from the start.
Better fuel management through the use of injectors (multi port and direct, e.g.Volkswagen's TDI)means a more accurate measure of fuel gets delivered to the cylinder. That results in a leaner mixture which in turn means a cleaner burn.
Catalytic converters clean up downstream exhaust just like the converter on your car. BTW: Mercedes is a leader in this technology.
The best part of diesels is the fact that with more complete combustion, there is less contamination of lubricants which means much longer engine life. The ignition system is eliminated and that means fewer brakdowns. AND, higher compression ratios and longer strokes can mean more HP and torque than in a gas engine.
The Jeep Liberty CRD uses an existing 2.8 liter Daimler diesel that has more torque than the 3.7 liter gas. It may be a bit slower off the line but it can tow like the 3.7 and has better mileage.
The bottom line: diesels run longer, use less fuel and generally have more power. Biodiesel fuel(e.g. soybean oil) can be mixed with diesel to reduce foreign oil imports.
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Kevin Buchanan 3:08PM (1/12/2006)
My TDI Volkswagen gets about the same real-world mileage as people with hybrids I know. Fun to drive, too. Diesels rock.
Around here, the price of diesel fluctuates. Can be anywhere from the same (or slightly less) than regular unleaded to about as much as premium. Right now, it's about as much as mid-grade at the nearest station from my house.
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Steve May 3:11PM (1/12/2006)
My wife and I recently drove our 2006 Jetta TDI from NC to OH. We filled up in NC and again in OH. We had traveled 586 miles on 12 gal. The trip took 9 hrs (plus change) with 5 stops (2 rest, 3 tolls). We also had quite a bit of luggage.
I don't think there is a hybrid which can approach the TDI! Love my TDI.
We only get around 42 around town.
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Steve May 3:20PM (1/12/2006)
My wife and I recently drove our 2006 Jetta TDI from NC to OH. We filled up in NC and again in OH. We had traveled 586 miles on 12 gal. The trip took 9 hrs (plus change) with 5 stops (2 rest, 3 tolls). We also had quite a bit of luggage.
I don't think there is a hybrid which can approach the TDI! Love my TDI.
We only get around 42 around town.
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NK 3:50PM (1/12/2006)
Having a Bluetec option on most vehicles would be sweet. Diesels last longer. they are usually designed to last 300K miles while gas engines are usually designed to las half of that. It is true that these engines do last longer. it is common for diesels to last over a million miles. the urea/ammonia would not be replaced at every fillup but rather replaced at every oill change.
How long will hybrids last?
the batteries are said to last for six years and wil cost a great deal to replace.
Bluetec is a system that clesns up the exaust and may be as easy to replace (the entire system) as a muffler or a catalitic converter
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Justin 3:53PM (1/12/2006)
Diesels get much better real world fuel economy than gas hybrids.
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goat 3:56PM (1/12/2006)
Peter,
Please note that the AdBlue is only necessary on the GL-class. The E320 BLUETEC uses a DeNOx absorber. No urea injection is required.
More info here:
http://www.greencarcongress.com/2006/01/daimlerchrysler.html
I'm not sure which system is used by the ML-Class.
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