Autoblog

GM's new 4.5L Duramax diesel engine promises a 25% increase in fuel economy while providing 310 hp and 525 lb-ft. The new oil-burning powerplant also needs to pass 50 state emissions while providing the efficiency customers are demanding. GM has already provided some details of the Duramax 4.5L, including that the new diesel is roughly the same size as the General's compact small block V8, which means it can fit in more than just trucks and SUVs. The 4.5-liter also reduces the parts count with integrated aluminum cylinder head exhaust manifolds and an integral cam cover intake manifold. GM talked to Automotive News about new features of the lower half of the 4.5L Duramax, and they're just as extensive as the top.

[Source: Automotive News subs req'd]

The car you see here is not a GNX. Hell, it's not even a Buick. You'd be forgiven if you thought it was, though, and it does sport a turbocharger underhood. David Morad was so enamored with the 6.6L LB7 Duramax diesel in his truck that he wanted to put it into something lighter and more fun. He decided to build a Grand National around the engine, and started buying up whatever applicable Buick body parts he could find -- right down to legit GNX dash plates. Next, he bought an '82 Buick Regal diesel that was to be the subject of the transformation. Unfortunately, that car literally self-immolated as he drove it home, sending Morad straight back to square one.

He subsequently found and bought an '81 Olds diesel and got to work. The car was cut in half so that a Regal rear end could be welded on, and then a laundry list of major modifications followed. To retain the stock Buick exterior appearance while incorporating the new powertrain, everything under the skin is is either extensively modified or custom fabricated in order to allow for the deception. Sure, it looks like a GNX, but this is really a scratch-built machine. Wilwood brakes lurk behind some absolutely wicked deep-dish Budnik wheels (dig those steamrollers in back), which nicely compliment the menacing black bodywork. Diesel Power magazine covers all the build's specifics in detail, and it's well worth a read.

If you're gonna masquerade as a GNX, you'd better bring some punch to the costume party, and Morad's car does. As of Diesel Power's publication, it ran an 8.25-second eighth of a mile, which they figure works out to somewhere in the 12s for the quarter. He'll be gunning for the 11s next, and additional performance upgrades are in store. Best of all? This is Morad's daily driver! He reports that it gets around 28 mpg in regular use and in the mid-30s on the highway. Not a bad combination: the looks of a GNX, the grunt of a big turbodiesel, and the fuel economy of cars that are a lot more boring. This thing had to cost a fortune to make, but Morad's clearly getting his money's worth on the fun scale.

[Source: Diesel Power via Next Autos]

New emissions standards in 2010 will make things too stringent for GM's Duramax diesel, in its current form, to make the grade. To help its prize student pass the looming tests, GM is investing $69 million in its DMAX plant (a joint venture diesel engine factory in Moraine, Ohio) for plant renovations and new machinery and tooling.

While GM doesn't really rate the uptake of diesel in the American market in passenger cars, the Duramax is an engine that has powered its fair share of GM sales. Since its introduction in 2001, more than one million Duramax diesels have found their way on the road in Chevy Silverados, GMC Sierras, full-size vans and some medium duty trucks. The current 6.6-liter Duramax V8 has a diesel particulate filter to meet today's standards. For 2010, GM will add a selective catalytic reduction NOx after-treatment system (along with the particulate filter) to meet the Tier 2 BIN and LEV 2 emissions standards. It will remain good to go in all 50 states.

[Source: GM]

At least one person has lamented the lack of diesel options for the H2 SUT. In case that's you, PickupTruck.Com speculates that the coming H2T (the new name for the H2 SUT, to bring it in line with H3T naming) could be offered with a diesel. The clue is in the big-bore tailpipe seen in the spy shots, which could indicate the use of a 'venturi-effect' tailpipe. It's the kind of setup GM uses on its Silverado and Sierra HDs to keep the oil burners from spewing black smoke.

PickupTruck also wonders if this is the first truck we'll see with GM's 4.5-liter light-duty diesel. Sure, it's all guesswork right now, but we're betting GM would make more than one person happy by offering diesels in its revamped H2 line -- especially if, as some people are saying, it's going to get even larger in its next iteration.

[Source: PickupTruck.Com]

Click the image above for more "Big Red"

Even though Chevy denies buyers a Z71 version of the Silverado 2500HD, it wants you to know how cool it could be. Say hello to "Big Red," powered by a 6.6-liter Duramax diesel backed by a six-speed Allison transmission, it combines a number of GM performance accessories with Rancho shocks and an "Earnhardt Red" paint scheme similar to that found on last year's NASCAR-legend inspired offering.

Chevy's full press release is posted after the jump.

In Parts 1 and 2 of his 2007 Heavy Duty Shootout, Mike Levine and his cohorts from Pickuptruck.com compared the acceleration of gas three-quarter ton and diesel one-ton pickups from Dodge, Chevy/GMC and Ford on flat surfaces, both unloaded and loaded with 10,500-lb trailers. For the third and final report, however, Levine introduced grades of 7% and 15% to the equation.

The results were surprising, and really had the most influence on Pickuptruck.com's final conclusions. We won't spoil the dramatic tail of each hill climb at Ford's Michigan Proving Grounds, but the 2007 Ford F-250 with its 6.8L Triton V10 was particularly impressive in the gasser category, and as anyone who has driven one would expect, the 2007 Chevy Silverado 3500 and its 6.6L Duramax diesel/6-speed transmission combo proved overly dominant among the oil burners. That said, the conclusions are only half the story, as Pickuptruck.com follows each truck through every gear as they climb their grades. These rigorous tests brought every truck's weakness, which were glaring in some cases, as well as their strengths.

Click the Read link below to read the conclusion to the 2007 Heavy Duty Shootout and learn once and for all what pickup these guys would park in their garage.

[Source: Pickuptruck.com]

Mike Levine from PickupTruck.com is our go-to guy for truck news. His brain is like the bed of a Ford F-450 filled with the esoteric details of heavy duty diesel pickups and 3/4-ton gassers. Plus, he's from the old school of automotive journalism and has made a successful transition to the web, which means his reporting is always knowledgeable and balanced despite it being delivered digitally. When Levine told us he was planning on doing a comprehensive comparo of today's heavy duty pickups, however, we were unprepared for the depth of the final product.

The 2007 PickupTruck.com Heavy Duty Shootout pits six HD pickups from Chevy/GMC, Ford and Dodge against each other on a totally level and unbiased playing field. Levine went so far as to hire a third-party company to perform all of the instrumented testing to remove any trace of subjectivity in the results. The players are three gas-powered 3/4-ton pickups including the 2007 Dodge Ram 2500 SLT Quad Cab 4x4, 2008 Ford F-250 FX4 Super Duty Crew Cab 4x4 and 2007 GMC Sierra 2500 HD SLE Crew Cab 4x4, and three diesel-powered one-ton pickups including the 2007 Chevrolet Silverado 3500 LT Crew Cab 4x4, 2007 Dodge Ram 3500 SLT Quad Cab 4x4 and 2008 Ford F-350 King Ranch Super Duty Crew Cab 4x4. Ford also threw in a 2008 Ford F-450 Lariat Super Duty Crew Cab 4x4 so that Levine and his team could attempt to prove how powerful this big rig really is.

We've just finished reading Part 1 and 2 of the three-part series, which includes an extremely knowledgeable and fact-filled introduction as well as the first battery of tests, including a "squat" test and 1/4-mile performance runs. Each part may appear like a lot to read, but we flew threw it faster than an unloaded GMC Sierra 2500 through the quarter mile.

Check out Part 1 here and click here for Part 2. The final installment should be out sometime this week, and we'll be eager to find out definitively which of these pickups outperformed its competitors in PickupTruck.com's battle royale of heavy duty trucks.

[Source: PickupTruck.com]

Mark your calendars, because we're calling today a watershed moment for the advancement of diesel's acceptance in the U.S. General Motors has just announced a new 4.5L V8 Duramax turbo-diesel powerplant it plans to use in the Chevy Silverado and GMC Sierra half-ton pickups, as well as the HUMMER H2. The new oil burner is expected to produce at least 310 horsepower and 520 ft-lbs. of torque. It features dual-overhead cams, four valves per cylinder, a variable-vane turbocharger and aluminum cylinder heads with integrated manifolding that helps keep the overall package small enough to fit in the same space as the automaker's small-block gas V8s.

That's right, just imagine the possibilities. Wherever GM uses a small-block V8 gas engine, it could potentially use the 4.5L V8 Duramax diesel. In a few years we could be driving diesel Impalas, diesel Camaros, maybe even a diesel Corvette! To quote GM's press release, the engine's small size gives it "the flexibility to introduce this engine in a wide variety of vehicle applications should there be future market demand." Indeed.

GM estimates that the engine will improve fuel efficiency by 25%, reduce CO2 emissions by 13% and decrease particulate and NOx emissions by at least 90% in its GMT900 pickups and the HUMMER H2. Whoever said the HUMMER H2 was on its way out will likely be proven incorrect after this engine debuts. Scheduled to be built at the GM Tonawanda engine plant outside Buffalo, NY, the 4.5L V8 Duramax diesel will be 50-state emissions compliant and meet 2010 diesel emissions standards, as well. GM claims its new diesel will also have NVH (Noise, Vibration and Harshness) levels approaching those of today's current gas V8s, though we'll have to wait and see if that wish comes true. That wait should end in a couple of years, as the automaker states the engine will be available in Silverado, Sierra and H2 models built after 2009.

UPDATE: Pickuptruck.com's Mike Levine has learned from GM that despite sharing its name with the older 6.6L Duramax diesel that was developed in partnership with Isuzu, the new 4.5L Duramax was developed completely in-house by GM.

Check out GM's full press release after the jump for more details.

[Source: GM]

Those looking for a glimpse into the future of light-duty diesel reliability may be interested in a new study by J.D. Power on customer satisfaction with modern heavy truck powertrains. The 2006 Heavy Duty Truck Engine/Transmission Study ranked engines from the 2004 model year by quality, performance, cost of ownership, and warranty, and revealed what one would reasonably expect from new technology.

An average of 74 problems per 100 vehicles was reported, which represents a 60% increase in trouble over the prior year. This was attributed directly to the emission control systems that were phased in during 2003 and 2004. Fuel economy also declined from 6.04 MPG in the 2004 study to 5.72 MPG - a drop of over 5%. Ranked highest in the study was Caterpillar, and the company's ACERT technology allowed the C12 and C15 (pictured above) to lead the ratings of individual engines. Unfortunately, unless you hold a CDL, it's highly unlikely that either one of them will find their way into your personal fleet.

So, what does this mean for consumers of passenger vehicles? Just as we've experienced the evolution of emission controls on gasoline engines, problems can be expected as manufacturers roll out clean diesel technology. How long it will take to sort out these issues is not yet clear, but we're guessing that things get sorted out rather quickly, and indeed some of the problems that are currently affecting heavy trucks may very well be eliminated before it trickles down to smaller oilburners.

[Source: J.D. Power; the complete press release is posted below the jump]

General Motors' recent (and vague) announcement of a new V8 diesel has led to significant speculation, especially with regard to power output and packaging size of the engine. As a preemptive strike against doubters, the company recently allowed Diesel Forecast to take a spin in a Buick Rainer equipped with the mystery oil-burner.

For starters, the "light duty" (intended for vehicles with a GVWR of under 8,600 lbs) will produce somewhere in the neighborhood of 330 HP and 520 lb-ft of torque. All that torque comes online around 1800 RPM and extends to 4500 RPM. We feel that these numbers should keep the average driver quite happy (diesel power junkies will just have to wait until aftermarket PCM tuners become available). For this we can credit the wonders of variable-geometry turbocharging, although at this point GM is not saying how many hairdryers they are using (two would be our guess, given the direction in which others are moving).

We were skeptical that a DOHC turbocharged V8 would fit into the same space as GM's ultra-compact pushrod gasoline V8s, but this does indeed appear to be the case (see the above outline drawing from GM, where its outline is shown against the GenIV L92). The fact that it fits under the hood of a GMT360 - a surprisingly tight environment, given the vehicle's external dimensions - speaks to the compact packaging of this engine, and means that we could see it popping up in just about any RWD product from the General.

On the emissions front, GM sees the engine utilizing urea injection with selective catalyst reduction to meet the EPA's 2010 Bin 5 regulations.

[Source: Diesel Forecast]