Shell Awards $1M to OSU for Hydrogen Technology Research
SeQuential Biofuels Opens Solar-Powered Biofuels Station

GM to Introduce New Light-Duty T2B5 Diesel for North America After 2009

General Motors will introduce a new V-8 turbodiesel that improves engine fuel efficiency by 25% for North American light duty trucks after 2009.

Environmental benefits of the new engine include a 13% reduction in CO2 versus gasoline engines, and at least a 90% reduction in particulates and NOx compared to diesel vehicles today. This will be GM’s first engine to use a NOx aftertreatment system along with a diesel particulate filter to help achieve the Tier 2 Bin 5 (T2B5) and LEV 2 emissions standards.

Technical highlights of the engine include aluminum cylinder heads with integrated manifolding, compacted graphite iron (CGI) block for a strong engine base and fracture-split main bearing caps and connecting rods for a precise fit. A high-pressure, common-rail fuel system is used, which has the ability to inject fuel five times per combustion event to control noise and emissions.

The new dual-overhead cam, four-valve V-8 diesel engine will fit within the same space as a small-block V-8 gasoline engine. This compact size is made possible by using an integrated air system and narrow block.

GM says that the premium V-8 diesel will deliver class-leading torque, power and refinement while maintaining a significant fuel efficiency advantage over comparable output gasoline engines.

This new GM light duty diesel is expected to become a favorite among customers who require excellent towing ability and fuel efficiency. It will meet the stringent 2010 emissions standards, and it will be compliant in all 50 states.

—Tom Stephens, group vice president, GM Powertrain

GM also announced that it has revised its Duramax 6.6-liter V-8 turbodiesel engine to meet 2007 federal emissions regulations.

Upgrades to the engine and a new diesel particulate filter system help ensure the engine meets government-mandated emissions regulations for diesel engines manufactured beginning in January 2007, which require a 90% reduction in particulate matter and 50% reduction in NOx.

To meet the new emissions regulation, the Duramax 6.6L V-8 engine features:

  • Additional combustion control, including an even more efficient variable-geometry turbocharging system, cooled (enhanced) Exhaust Gas Recirculation (EGR) and closed crankcase ventilation to reduce NOx.

  • Additional exhaust control, including oxidizing catalyst and new Diesel Particulate Filter (DPF) to reduce soot and particulate matter.

  • Increased-capacity cooling system.

  • New engine control software.

  • Use of low-ash engine oil.

The new Duramax 6.6L V-8 (LMM) engine offers versions with 300 hp (224 kW) and 520 lb-ft (705 Nm) of torque, as well as a new 330 hp (246 kW) option with 620 lb-ft (841 Nm) of torque.


Sid Hoffman

Hang on, a quad-cam, 32 valve V8 with aluminum heads, variable geometry turbo, and a high pressure common rail injection system? Are my eyes playing tricks on me or is this really a GM engine? This sounds like great news, although for light-duty trucks, 6.6 liters and 300hp/520ft-lbs is still massive overkill. A 4.0 liter V8 would still provide all the torque of a 5.7 liter gas engine and the fuel economy of a 3.5 liter gas V6.


A V8 turbodiesel would be great for people who buy GM's core vehicles, large SUVs and trucks, but what about us folks who only need around 120 horsepower? Where's the GM innovation there?


future engineering says goodbye to b-fuels



Did you see this from yesterday????

Sid Hoffman

Icelander, it's a lot like hybrids. The newest diesel engines include a lot of technology that is new and expensive. I believe you pay $6000 extra for a diesel engine in a GMC 2500 truck versus the gas engine. Would you pay $6000 extra, or even $2000 extra for a diesel engine in your Civic, Corolla, Cobolt, or otherwise? Probably not, so they are using diesel in the most expensive offerings first until the technology is developed enough to make it possible at lower cost levels.


Sebastian, what's your deal? These vehicles will have to be able to run on at least B20, as this is the highest likely level to be mandated by any given US state over the next 5 years. Also, Europe and South America are already mandating small percentages of BD. So stop saying stuff like that as it is not true.

fyi CO2

So now they'll only produce 10 tons of CO2 annually?
Mute the blaring trumpets - a 25% increase in fuel economy in this segment represents 2-4 mpg



Given the number of such vehicles on the road already and the popularity of the segment, a 2-4 mpg increase is petty good. And diesels are far better for towing than gasoline. Some commenters here have reported almost double the fuel economy compared to gas for those purposes.

Looks good to me.

Bike Commuter Dude

Does anyone know if this one was designed by the General, or was it Isuzi? Duramax Diesels are basically rebadged Isuzi Diesels. Isuzi is good at what they do, but I have heard that they tend to burn out/destroy injectors. I don't know if this will be a problem with the new design, or with the widespread use of <15ppm ULSD.


25% is nothing to sneeze at!


ULSD (ultra low sulfur diesel) does not lubricate as well so if the IsuzU (yes with a "U" not an "i" which would be pronounced like long "E" making it sound like suzie) injectors have trouble with standard diesel they must have made significant changes...or they are in for some serious trouble.


Hate to be a pessimist but I suspect GM will just increase the size of their SUV's and Pickups into mega SUV's and pickups and counter all the new efficiency if the past is any indication. Would'nt it be nice if they would use this technology in a sedan or even a hybrid diesel electric sedan?

Sid Hoffman

Patrick, I have one of GM's "Live Green, Go Yellow" t-shirts in my closet that I got for free when they were hyping their commitment to E85. GM knows they need to embrace biofuels to survive and USA is both corn and soy country, so they have to be very motivated to make sure their trucks will run on soy-based Biodiesel. Then they can tout not only all thier E85 flex fuel vehicles but their Biodiesel capability too! It's to GM's best interests to support all biofuels, not just ethanol, so I am positive they have tested biodiesel, even if they didn't certify it with this engine yet.


Sid, my comment was in regards to the sentiment put forth by Bike Commuter Dude of whether or not the Isuzu injectors (which he believes fail often due to hearsay accounts) would survive in ULSD. This has nothing to do with GM's diesel and their commitment to any type of fuel...unless they ARE using these "low quality" injectors of which Bike Dude speaks...and I even mentioned that if there were any problems of injector failures with standard diesel then they would have replaced these troubled injectors and targeted ULSD fuels for performance specifications (of reliability & longevity). Therefore, I am unsure of the applicability of your comments to my comment.

Walt D.

The bigest problem with Diesels in the USA is that we have the Eco-Police passing CARB Standards, and things like T2B5 emissions standards which do not include requirements for the Oil Companies to provide fuel that makes it possible to pass the tests.

ULSD (<15 ppm sulfer) is a step in the right direction, but until the Feds or the majority of the states require 10ppm Sulfer Diesel, that is minimum 52 cetane and has a standard aromatics package, it is going to be very herd for any mfg to sell Diesel passenger vehicles in the USA.

This is also helping the oil companies keep BioDiesel out of the mainstream. I'd like to see 2% USA Made Biodiesel (B2) in all Diesel sold in the USA, on and off road, by Jan 2008, as federal law. That would promote some more biodiesel production. I'd also like to some mandates that at least 10% every major chain (Chevron, Exxon, Shell) be required to have at least 1 B5 pump installed.

The only major "chain" of you will (and I consider them a friend of the farmer - not "Big Oil") is Cenex. Those who are fans of BioDiesel should support Cenex brand fuel stations whenever possible. They market and sell Biodiesel blends, like their B2 Ruby Fieldmaster for Off road. I realize they aren't sell biodiesel at thier pumps at every station, but if given a choice when filling up a vehicle with Petrolium Based Diesel or gasoline (which ever is required by the vehicle) and I have a choice between Cenex, Chevron, Texaco, Shell, etc, I'll choose the Cenex thank you very much!

allen Z

GM could shrink the engine by reducing the number of cylinders. A 4, 5 or 6 cylinder (3.3L, 4.125L, 4.95L) version could power many vans and small to mid sized commercial pickups. It would have commonality with the other vehicles for scale of economy sakes. GM's european divisions could help on smaller engines. Needless to say, no doubt military HMMWV users (esp US Army due to equipment rebuild efforts) will want these. Finally, if GM and Nissan/Renault get together there are a few things GM might want. Specifically, the carbon (diamond?) friction reducing liner in the gas engine Nissan unveiled will be of upmost interest to GM.

allen Z

"other vehicles for scale of economy sakes"
not vehicle, er, engine. The engine block and a few other components would be the only things different.

Herb Sewl

I wish they would make a small diesel pickup like they used to build in the 80s. I don't need a 300 HP V-8 to haul a couple of bags of potting soil from Home Depot.

allen Z

Herb Sewl,
A Chevy Colorado/GMC Canyon/Isuzu Rodeo/Isuzu i-Series pickup with a shrunken 2.2L I4 w/ 100hp 174lb/ft version will do just that. Now for them (GM top management) to figure this out.


wait, "light duty" diesel? 300 hp (224 kW) and 520 lb-ft (705 Nm) of torque, thats kinda light... wonder how heavy is heavy.


sorry for this, its just that i´ve also read about biodiesel in the pretty reliable german magazine "auto motor und sport" and they say biodiesel is poison for dpf, but i am a actually happy to see that it may be okay.
unfortunately they don´t say anything about the injector systems this could be interesting

Walt D.


Do some research folks...

#1 The injectors in the Duramax engines (current) are Bosch Supplied and are laser etched with a serial number -Every injector in every engine is tracked.

#2 The Specs for ULSD include a minimum addatives package that includes a minimum lubricity. So, we likely won't see the issues like we saw in 92/93 when Sulfer dropped to 500ppm. There are some reports of leaking seals already, and speculation is that is is from ULSD - but no failing pumps

#3 As I stated above, ULSD doesn't go far enough - there are no mandates for Minimum Cetane and Aromatics levels. So 38 to 45 cetane fuel is common in the US while 52 is the minimum in Europe. Aromatics is a complete crap shoot in the US.

#4 If owners are really concerned about ULSD lubricity, then just use 5% biodiesel in the tank - problem solved. On top of that, users of B5 up to about B20 routinely report increased fule milage and less smoke.

#5 GM doesn't need to cut off cylinders or shrink this design... They already have good small diesel designs of thier own - Go to the GM site and take a look at the vehicles and fuel efficincy numbers there... Can you say "Minivan that gets 40+ on the freeway?" - Vauxhall can.

#6 GM, Ford and Chrysler could all bring thier great Europen clean high efficiency diesel desings to the USA if the CARB states would adopt the European Emissions standards and all states would mandate the European Standards for Diesel fuel quality - it is that simple.

#7 The Oil Companies are the only ones winning with the current situation. They have the best of it. The Envro-Police in places like California are keeping the European Clean Diesels out, and will likely do so because the Gov. Officials are all bought off by Big Oil. This is obvious becasue while mandating clean emissions standards, they aren't mandating clean fuel standards. ULSD is so late getting into the system, it isn't even mandated until Oct 1, and even then not all stations have to carry it. This is why long time Diesel supporter VW isn't even going to sell Diesel sedans at all in 2007. They don't want to run the risk of a consumer putting the wrong fuel in thier car and ruining the emissions system. Even thier 2006 V10 Diesel Toureg is being "held back" in the US market - rumor has it that they are all in the US in a wharehouse somewhere waiting for the ULSD to be in the channel.

Last, don't beieive everything you read on the Internet, research for yourself by referencing other sources.


GM's "Live Green, Go Yellow" gimmick is nothing more than:
"Guzzle ethanol instead of gasoline" BFD!

allen Z

__Write to your Congress Rep. or Senator. It is election time, and maybe we can get something done (or at least get the wheels of political legislation moving). After all, high gas prices is a beef amongst voters this year. Perhaps we can apply some pressure on them through political campaigns to speed up the >15ppm ULSD (with the biodiesel), and the >10ppm ULSD down the road. Oil execs say that they are reinvesting profits in current and future operations. With pressure to show something tangible for all those profits, maybe they can be prodded into doing this. If the companies with refinery ops, and running a profit, use their money to upgrade, then we can have cleaner air sooner. I doubt Conservatives like their children sucking polluted air into their lungs anymore than Liberals do.

Walt D.

Great idea.

I think if we even just ask for Diesel to meet the standards that they have in Europe (Here we would need some plan like 10ppm Sulfer June 2008, 52 Cetane Minimum by Jan 2008)

Also require B2 (2% Biodiesel by June 2008 - I know I am giving up 6 months to what I asked for above)

Last, get the CARB states to loosen up to Euro 5 standard from Jan 2008 until Jan 2011.

This would allow some Clean Diesel Engines and Vehicles to be brought over from Europe, at least for a year or two - and allow for some more development time to meet CARB with good fuel.

I think with some work on BioDiesel Availability and some work on Engine control to allow for BioDiesel blends (Even at B2 level) we could see some great reduction in need to foreign oil without sacraficing air quality or quality of life.

Regardless - we are going to see developement in the area of Diesel engines, it is just going to be slow without taking advantage of the designs they already have in Europe. We need help now in the USA - not 5-6 years of lining the pockets of the OPEC powers.

The comments to this entry are closed.