• 30

Click above for a high-res gallery of the MB GL320 BlueTec

Urea injection will finally arrive in the U.S. when Mercedes-Benz launches fifty-state-legal diesel versions of its ML320, GL320 and R320 BlueTec models. Mercedes says these U.S. light-duty diesels will be equipped with AdBlue injection that allows them to meet this country's strict Tier2 Bin5 emissions standards. To live up to that, Mercedes will have to ensure that vehicles are shipped before BMW gets the X5 and 335d into customers hands this fall. The Mercedes vehicles are using a 3.0L turbo diesel V-6 putting out 210 horsepower and 398 pound-feet of torque, while using urea injection (like the diesel BMWs and upcoming diesel VW Touareg and Audi Q7) to almost completely eliminate NOx emissions. Called AdBlue, it is a solution of 2/3 water and 1/3 urea that reacts with NOx to create nitrogen and water.

The urea is contained in a 7-gallon (8.5-gallon in the larger GL) tank that should only need refilling about every 15,000 miles. In addition to the urea NOx treatment system, the trio also have diesel particulate filters to eliminate almost all of the soot. With these vehicles being T2B5 compliant, that means they will also meet the future Euro6 standards. The ML- and R-class diesels will be rated at 18/24 mpg, while the heavier GL comes in at 17/23. That compares to 15/20 for the ML350 with a gasoline V6 and 13/18 for the ML550 with a V8. The E-Class sedan will also get the urea treatment in 2009 after the next generation model debuts.

[Source: Mercedes-Benz]


R 320 BlueTEC, ML 320 BlueTEC and GL 320 BlueTEC: The cleanest solution: Mercedes-Benz to introduce the first diesel models with AdBlue injection in America

Stuttgart – Mercedes-Benz is continuing its diesel initiative in the USA with three new SUVs equipped with the world's latest and cleanest diesel engine. The new models R 320 BlueTEC, ML 320 BlueTEC and GL 320 BlueTEC will initially be available exclusively in America. They are powered by an up-to-date V6 engine featuring the environmentally friendly Mercedes-Benz BlueTEC technology, with whose help the diesel cars produced by the Stuttgart manufacturer already count as the world's cleanest. The new models are equipped with AdBlue injection, which has already been demonstrating its exemplary effectiveness and economy in Mercedes-Benz trucks and buses for a number of years. As a result the three new SUVs achieve even lower emissions, are able to better the stringent Bin 5 limits applicable in the USA, and also have the potential to meet the coming EU6 standards. All three of these new SUVs have also been significantly upgraded with much more extensive standard equipment, and now offer even more comfort together with unique safety features. With these diesel vehicles Mercedes-Benz is once again underlining its status as the technological leader. The new models will be available in the USA from autumn 2008.

In October 2006, Mercedes-Benz was the first manufacturer to commence a BlueTEC initiative in the passenger car segment which was timed to coincide with the introduction of low-sulphur fuel in the United States of America. The E 320 BlueTEC proved a great success from the outset, and was voted "World Green Car of the Year 2007". As a next step, Mercedes-Benz is now due to offer the R, ML and GL 320 BlueTEC in the USA, the world's first three diesel cars which not only meet the particularly demanding criteria of the American Bin 5 standard, but also have the potential to fulfil the stringent EU6 standard due in the future – and which therefore considerably better all the current, worldwide exhaust emission standards for diesel passenger cars.

With attributes such as excellent pulling power, economy and a high output, the diesel engine has also proved an attractive alternative to the spark-ignition engine in the USAin times of increasing fuel prices and growing sensitivity to the issue of CO2 emissions. In the land of large minivans, pickups and SUVs, and the given driving conditions characterised by steady cruising speeds on the high-ways and enormous overland distances, the diesel is able to show its advantages particularly well. At the same time, American legislation sets very strict emission standards for diesel-powered vehicles. This is why Mercedes-Benz introduced the E 320 BlueTEC with its in-house BlueTEC technology in America first, and is now including a variant of this BlueTEC technology with AdBlue injection in its cross-Atlantic range. This innovative drive technology enables these large and powerful SUVs to meet the limits imposed by the US Bin 5 standard.

Impressive power, great fuel economy and extremely low emissions
The muscular V6 diesel engine powering the new BlueTEC models in the GL, M and R-Class shows that a low fuel consumption and very low emissions are also possible for large SUVs. It has an output of 155 kW/211 hp and develops a torque of 540 Nm. Fuel economy is outstanding: the GL 320 BlueTEC, for example, consumes just 9.5 litres of diesel fuel per 100 kilometres (25 mpg). This represents an advantage of around 20 to 40 percent versus a comparable petrol model, and easily makes the Mercedes-Benz GL 320 BlueTEC the most economical full-size SUV in the USA.

Certain features of the six-cylinder diesel engine had to be modified for use in the new models ML 320 BlueTEC, GL 320 BlueTEC and R 320 BlueTEC with AdBlue injection. The piston crowns were revised for an improved mixture formation, and the compression ratio was reduced from 17.7 to 16.5. The VNT turbocharger and engine control unit were also improved and reconfigured. All three of the new SUVs are available only with the 7G-TRONIC seven-speed automatic transmission.

Nitrogen oxides drastically reduced with BlueTEC
As a modular concept for an effective reduction in the fuel consumption and emissions of diesel vehicles, the BlueTEC technology developed by Mercedes-Benz puts in place a number of coordinated measures which both minimise untreated emissions using in-engine features and ensure efficient exhaust gas aftertreatment. All relevant emissions components are successively and concertedly reduced to a minimum, in part by using an oxidising catalytic converter and a particulate filter. The most important goal is to achieve a drastic reduction in nitrogen oxide emissions, the only exhaust gas constituent which has inherently higher levels in diesel engines than in petrol engines. Mercedes-Benz has developed two versions to this end. In the E 320 BlueTEC Saloon available in the USA and the E 300 BlueTEC sold in Europe, an oxidising catalytic converter and a particulate filter are combined with a particularly durable NOx storage-type catalytic converter and a special SCR (Selective Catalytic Reduction) converter. The second BlueTEC version is used for the new GL 320 BlueTEC, ML 320 BlueTEC and R 320 BlueTEC models. In this case AdBlue, an aqueous urea solution is injected into the stream of exhaust gases. This releases ammonia, of which 80 percent is reduced to form harmless nitrogen and water by the downstream SCR converter.

This innovative emissions control technology follows the following stages:
Optimisation of the engines and their combustion processes to reduce untreated emissions as far as possible. These measures include electronic enginge management, four-valve technology, third-generation common-rail direct injection with piezo-electric injectors, a turbocharger with variable turbine geometry and exhaust gas recirculation.

Oxidising catalytic converters are used to minimise emissions of carbon monoxide (CO) and unburned hydrocarbons (HC).

A particulate filter, which has been standard equipment in all Mercedes-Benz diesel models in many countries since summer 2005, reduces particulate emissions to a barely measurable level. This easily meets both the current EU4 particulate limits (0.025 grams/kilometre) and the current US limits.

Nitrogen oxides are reduced by a storage-type Nox catalytic converter combined with an SCR catalytic converter, or by AdBlue injection combined with an SCR catalytic converter. These effective aftertreatment methods allow the nitrogen oxide emissions of BlueTEC vehicles to be reduced by up to 80 percent.

AdBlue injection specially advantageous in large vehicles
Whether a storage-type Nox catalytic converter or AdBlue injection is used depends on the individual vehicle concept and the prevailing market conditions from case to case. AdBlue technology has advantages for large saloons, pickups and SUVs, as the engine does not need to operate with an intermittent, rich combustion mixture to clean the storage-type Nox catalytic converter which removes the harmful nitrogen oxides from the exhaust stream. This would be necessary at frequent intervals in the case of heavy vehicles with a relatively high fuel consumption, and would lead to an even higher consumption.

In the case of the urea-SCR process, the reducing agent AdBlue is injected into the exhaust tract. This is an aqueous urea solution which is carried in an auxiliary tank. When injected into the hot, pre-treated exhaust gases, AdBlue is first broken down into its constituents of water and urea. From around 170 degrees Celsius the urea is converted into ammonia (NH3) – the actual active agent in this process. The ammonia is stored in the catalytic converter, and reduces the nitrogen oxides into harmless nitrogen when exhaust gases containing nitrogen oxides flow through the catalytic converter. The engine management system controls the injection of AdBlue in such a way that the ammonia reservoir of the SCR converter always contains some but never too much ammonia. This is monitored by an Nox sensor.

A small AdBlue tank is sufficient
The urea solution is held in a separate onboard tank, and fed to the metering module by means of a pump. As the average consumption of AdBlue is only around 0.1 litres per 100 kilometres (or 1 to 3 percent of diesel consumption), the tank can be of such a size that it only needs to be refilled at the workshop during regular service intervals. The tank capacity is 28 litres in the R 320 BlueTEC and ML 320 BlueTEC, and 32 litres in the GL 320 BlueTEC. Even under more demanding conditions with a higher AdBlue consumption, e.g. when towing a trailer, this is sufficient to avoid the need for unscheduled refilling stops in the workshop. This means that the customer has no need to concern him- or herself with the AdBlue level in the tank. Should the AdBlue level unexpectedly fall below a certain level nonetheless, the electronics provide a timely warning.

More extensive equipment and visual modifications With these innovative BlueTEC models in the R, M and GL-Class, Mercedes-Benz is not only demonstrating the potential of the diesel as a drive system, but also offers tailor-made solutions for the high expectations of the premium segment with the widest range of SUVs. The R-Class particularly excels with its outstanding long-distance comfort, and with the most generous and variable interior with up to seven seats. The M-Class is the most successful Mercedes-Benz Sport Utility Vehicle, and is seen as the trailblazer for all modern premium SUVs. And with the GL-Class, Mercedes-Benz occupies the peak position in the entire SUV world – its occupants enjoy first-class on-road and off-road travel under all conditions.

All three SUVs have now been revised in numerous respects. The modifications to the M-Class are the most comprehensive of all. The new generation of this dynamic SUV now has even more striking characteristics, and appears even more sporty and powerful. The front and rear ends have been redesigned and given a stylistically updated and youthful touch. The front end of this off-roader is now defined by a redesigned bumper, re-contoured headlamps and a larger, even more dominant radiator. The rear aspect also has a redesigned bumper with inset reflective strips to emphasise the vehicle width, as well as tail lights with smoked-glass lenses. Stylistic fine-tuning and new materials which are pleasing to the eye and touch combine with a new two-tone colour scheme to add fresh highlights to the interior. One eye-catching feature is the new four-spoke multifunction steering wheel, which the GL and R-Class will also receive.

The standard appointments for the M, R and GL-Class have also been significantly expanded. They now include the unique, preventive occupant protection system PRE-SAFE® and NECK-PRO head restraints, as well as a new, Mercedes-Benz developed telematic system with further improved user friendliness, high performance and numerous additional functions.

More performance, more comfort – new-generation telematics
A completely newly developed generation of telematic systems developed by Mercedes-Benz will be used in SUVs in future. These excel with even greater user friendliness, a high performance and numerous new functions. Integrated features include a hand-free system based on Bluetooth technology, and an Aux-In connection for mobile audio units such as an iPod. On request there is also a new Media Interface, which can connect an external music source with the onboard electronics and control system of the off-roader, enabling music tracks to be shown in the instrument cluster and the colour display in the centre console, and conveniently accessed using the keys on the multifunction steering wheel. At the same time the battery of the audio unit is charged.

There is a choice of three units, all of them with a colour display, a twin tuner for improved radio reception, speed-sensitive volume control, a keypad for entering telephone numbers and radio frequencies and a Bluetooth interface which enables a mobile phone to be wirelessly linked to the hands-free system.

In the USA there is also the option of an HD radio and SIRIUS satellite radio. In conjunction with the new telematics generation, Mercedes-Benz also offers the optimised LINGUATRONIC voice control system as an option.

The occupants are also able to enjoy a surround-sound experience of concert hall quality with the latest generation of the optional harman kardon® Logic7® sound system. With its high output and digital signal processor (DSP), this ensures outstandingly transparent listening pleasure.

As a further option, passengers in the rear can be provided with a rear-seat entertainment system featuring two large, 8-inch screens, a DVD-player, two wireless headsets for more freedom of movement and a remote control unit.

Unrivalled safety features as standard
In the SUV segment too, Mercedes-Benz vehicles have always been exemplary when it comes to safety. In future the R, M and GL-Class will be supplied with the preventive occupant protection system PRE-SAFE® and NECK-PRO head restraints as standard equipment.

Mercedes-Benz is the trendsetter for diesel cars
As long as 70 years ago, Mercedes-Benz was the first manufacturer to use the combustion principle pioneered by Rudolf Diesel in a passenger car engine. This technology has a much higher efficiency than the spark-ignition engine, and has been steadily improved over many years. One decisive technological leap forward led to the development of the modern diesel in 1997: the introduction of common-rail direct injection in combination with four-valve technology. Since then the abbreviation CDI has stood for both unrivalled fuel economy and an enormous increase in torque – a synonym for a level of pulling power which guarantees plenty of driving pleasure and often makes diesels superior to petrol models developing the same output.

If the diesel has previously had any disadvantages versus the petrol engine, this has been in the area of its specific emissions – above all soot particles and nitrogen oxides. Ever since the introduction of the maintenance-free particulate filter from autumn 2003, Mercedes-Benz has however also set the best example where particulates are concerned. And despite having achieved a reduction in nitrogen oxides by around 75 percent thanks to in-engine measures over the last 15 years, Mercedes-Benz has not been content to rest on its laurels in this respect. Equipped with innovative BlueTEC technology, which was introduced for the first time in a passenger car in the USA, the high-tech diesel engines from Mercedes-Benz meet the world's toughest exhaust emission limits. While AdBlue injection makes the new M 320 BlueTEC, R 320 BlueTEC and GL 320 BlueTEC the world's cleanest diesel SUVs.

I'm reporting this comment as:

Reported comments and users are reviewed by Autoblog staff 24 hours a day, seven days a week to determine whether they violate Community Guideline. Accounts are penalized for Community Guidelines violations and serious or repeated violations can lead to account termination.

    • 1 Second Ago
      • 7 Years Ago
      You have to fill the urea tank every 15,000 miles. So, What do you do, pee in it? I think that would be an adequate mixture of urea and water.

      This gives new meaning to having someone piss in your tank.

      I think all SUVs should have their tanks pissed in if they don't get used for off road purposes or towing.
      • 7 Years Ago
      urea injected?!?!!?
      holy ish! this thing is going to run on diesel and urine!
      • 7 Years Ago
      @ Maxzillian

      Carbon doesn't aid the combustion, but the bonds between carbon and hydrogen (which are broken for energy during combustion) are what combustion is all about, hence the correlation between CO2 and energy density of diesel.
        • 7 Years Ago
        I don't completely agree. Carbon is an aid in combustion, because it's another thing that gets burned. So more things to burn, more energy is released.

      • 7 Years Ago
      This is ridiculous. These vehicles get 18 (17 for the GL) mpg city. A Tahoe hybrid gets 21. Also, the Mercedes requires Diesel, which is about 10% more costly than the regular gas the Tahoe takes. Oh, and the Tahoe is far bigger.

      Looks to me like in this case, the hybrid is doing far better than a Diesel at running costs.

      Mercedes needs to do a lot better than this I would think.
      • 7 Years Ago
      Is it really worth it? Don't forget that part of the key to diesel MPG is the fact that it contains 20% more carbon per gallon, hence during combustion you get 20% more CO2 per gallon. Combine that with higher NOx and particulates and you aren't doing mother nature any favors. Since the car gets only 20% better fuel economy and diesel is rapidly approaching a 10-15% premium, how much are you really saving? Gasoline is cleaner, performs better, and there are still quite a few efficiency refinements to be had there such as stratified charge direct injection.

      If Toyota can get 19/27 MPG from a 269 horsepower awd RAV4 that doesn't even have direct injection, I think there's a lot more future in gasoline engines than people think.
        • 7 Years Ago
        I guess my point is really that the incremental improvement for these Mercedes diesels is much less than expected as they only appear to boost efficiency by ~20%. So from a CO2 standpoint they are neutral and the cost advantage is dwindling due to the increase in diesel prices in the US relative to gasoline.
        • 7 Years Ago
        The key to diesel efficiency isn't the amount of carbon in the fuel as carbon doesn't aid combustion at all. The key is that diesel contains roughly 15% more energy content than gasoline and diesel engines tend to be more efficient largely from the reduction in parasitic losses (the engine isn't sucking on a vacuum during normal cruise operation) and a slightly more efficient combustion process.

        Because of this higher fuel efficiency, diesel cars generally come out about equal for emissions in comparison to gasoline cars. The only problem, obviously, has been sulfur emissions due to the sulfur content of the fuel and NOx emissions due to the higher combustion temperatures of a diesel.
        • 7 Years Ago
        First of all it's Sam not Samuel. I didn't say diesel didn't have more carbon. But for a given engine output, the result is fewer gallons used and less carbon dioxide compared to a gasoline engine.
        • 7 Years Ago
        Sorry. I misunderstood. My original thread was really about the ML bluetec, which doesn't have the 40% additional efficiency you quote. Given the additional CO2, low incremental mpg, and cost of diesel, I don't see how these cars make a lot of sense in the US market. Sure, a Ford Focus TDCi would be another story but the diesel advantage seems to evaporate in luxury SUV's where performance is more of a priority than efficiency.
        • 7 Years Ago
        Actually it doesn't take any more crude to produce a gallon of diesel than it does for gasoline. Diesel comes off lower in the distillate tower than the compounds that are blended to produce gas and it is more dense. The diesel cycle is inherently more efficient than the otto cycle and combined with lower losses from the absence of a throttle, the full powertrain is typically about 30% more efficient. It also produces 20-30% less carbon dioxide than gas engines. Diesels are more expensive to produce and currently the fuel is also more expensive in the US.
        • 7 Years Ago
        Energy density per gallon is not really the issue here.

        It's about the up-front premium for the diesel plus DPF plus urea injection, depreciation, fuel cost per mile and if you care, CO2 emissions per mile.
        • 7 Years Ago
        Yes, a gallon of diesel contains 15% more carbon than a gallon of gasoline, so it will put out 15% more carbon per gallon of fuel consumed. But, diesel engines use compression ignition and run at significantly higher compression ratios than gasoline engines, so they extract more work out of each unit of energy put in.

        A 40 mpg diesel will put out more CO2 than a 40 mpg gasser. If you only look at energy content, the fuel economy would go up to 46 mpg. However, a proper diesel engine would bump it up to 55-60 mpg.
        • 7 Years Ago
        Sorry Samuel,

        I call BS. According to the EPA, Diesel has 15% more carbon per gallon.

      • 7 Years Ago
      They need to take the R-class to the back, and put it out of its misery.
        • 7 Years Ago
        I looked at both of these at the autoshow recently. I'd take the R class every single time. More room, better mileage, lower centre of gravity...

        ...and because they're not selling well, they're a screaming deal.
      • 7 Years Ago
      stephen @ Mar 13th 2008 6:02PM "Another thing nobody thinks about. The diesel engine in the jeep suvs and mercedes whatever is only a 3.0L. Is it possible its working a little hard when compared to the upwards of 5 litre gas engines in the same truck? Just a thought."
      My answer is: GC's 3.0Lcrd 215 - 218hp 376lb-ft is up to the job. The previous motor used in the Jeep GC was a I-5 2.7Lcrd 161hp 295lb-ft and that motor was the standard for the heavy sprinter 3500 (154hp 243lb-ft) where gross vehicle max weight is 8550 lbs.
      For European sales they offer for the 2007 MB sprinter 3500 besides the 3.0L 184hp 400Nm 295lb-ft, they offer the 2.2Lcrd 150hp 330 Nm 243lb-ft & 109hp 280Nm 207lb-ft. Note: for US sales the 3.0Lcrd dodge sprinter 3500 is rated 154hp 280lb-ft. So I think (my opinon only) if the company wants the motor to last longer (meet longevity goals for warrenty, for the weight it needs to haul) they put less turbo pressure in the motor and lower the hp & lb-ft.
      • 7 Years Ago
      brings a new meaning to, "pull over, I gotta pee."
      • 7 Years Ago
      Take that California!
      • 7 Years Ago
      I've never been a diesel fan, but all that torque!
      It's boat-towin time!
      • 7 Years Ago
      First, a diesel engine that provides the same power as a gas engine typically provides far greater than a 20% boost in fuel economy.

      Second, I wonder if we're going to see any kind of stricter emissions on "personal-use" heavy duty diesels? I mean, we get so caught up in making sure that the already fairly clean diesel car engines are somewhat cleaner, and quite happily encourage people to buy 350hp Cummins diesels to drive themselves to the office... seems a little weird.
        • 7 Years Ago
        Unlikely. The small businessman--and especially the small farmer--is practically the living embodiment of Christ in the US and no politician who intends to get reelected is going to propose something that might be construed as hurting the Little Entrepreneur.

        Now, you could argue that a lot of these trucks are bought be big business, that they could probably use smaller trucks without much impact on their workflow and/or that a lot of them aren't bought for business at all. And you'd be right, but it wouldn't stop Monsanto or General Motors taking out a "Your Tax On Trucks Hurts Bob the Farmer" ad campaign.

        It's a lot like the ethanol boondoggle, really.
      • 7 Years Ago
      Using just the ML as the example...

      Right now, to get the non T2B5 compliant diesel, you pay a $1000 premium. For this you get only 3 mg city/4 mpg hwy better mpg; marginally better greenhouse emissions (a 1 point difference on the EPA's greenhouse scale); horrid emissions (Bin 10); and slightly slower performance. All while paying 30-50 cents more per gallon of fuel.

      Already sounds bad to me..... but add urea....

      (purely speculative from this point on, but based on best current information) add another $1-2000 to the bottom line. Watch mpg and performance go down slightly, while CO2 emissions increase slightly, which adding emissions components invariably leads to. While still paying extra each week at the pump.

      Bluetec may be the way to make diesels finally acceptable to the US. But are the compromises worth all the effort? When gasoline engines have come so far. When you can get an hybrid RX400h that trumps the ML diesel in just about every category, and will continue to do so even after pee is injectd into the ML's tank.
        • 7 Years Ago
        The current popularity of diesels in the uk is due to tax levels, particularly company car taxes based on co2. diesels now provide similar power and refinement to petrol engines although do need turbos, soot filter and some kind of nox filter but produce less co2. The government are now getting very serious on green issues, or they want the extra taxes ! Either way
        higher emissions cars are not viable any more here, even though in the UK diesel is more expensive. Diesels retain more value than petrol cars second hand.

        Cars emitting over 225 gm of co2 will pay £25 PER DAY to go into London. Over 120 gm will pay £8 PER DAY but under 120 gm will pay ZERO (until more people buy 'em!)

        You might prefer the 2.oT A3 petrol and be tempted by the 140bhp tdi but the latest 105bhp tdi is under the 120 mark. It may be slow and not much more economical than the normal tdi but will save £8 every day
    • Load More Comments