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2011 GMC Sierra Denali HD – Click above for high-res image gallery

As you may have noticed, automobile sales are picking back up after their seemingly perpetual nosedive of the last two years or so. The same holds true for fullsize pickup trucks, and we're hoping that this resurgence will bring back some of the more interesting developments that had to be shelved due to monetary constraints. Chief amongst these wishes are the unfortunately abandoned light-duty diesel engines from Dodge, Ford and General Motors.

With that in mind, our interest is piqued by a report from our friends at PickupTrucks.com suggesting that the previously shelved 4.5-liter Duramax diesel V8 engine from GM may be back on the table, except with an interesting twist. While the oil-burning powerplant was originally intended just for half ton trucks, GM is reportedly now considering offering the mill in all of its fullsize trucks, including the Heavy Duty models.

General Motors indicates that its 4.5-liter diesel V8 engine is "fully developed and ready" to launch with power ratings of over 310 horsepower and 520 pound-feet of torque. Those figures would just about match what the larger Duramax diesels were putting out about a decade ago and seemingly be plenty for the 2500 class of trucks. What's more, The General told our own Sam Abuelsamid that the still-running fleet of 4.5 diesels is averaging an impressive 25 miles per gallon.

[Source: PickupTrucks.com]

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    • 1 Second Ago
      • 5 Years Ago

      This engine should have been released a long time ago. The 2500 Suburban especially, as the 6.0L gas engine gets terrible fuel economy (single digit fuel economy around town or pulling a trailer). As I've been saying for years, as soon as they release a new diesel 2500 Suburban/Yukon I'll replace my 1995 diesel 2500. Otherwise, I'm keeping that truck until the wheels fall off.

      Really, this engine is a perfect candidate for the Suburban/Yukon, the Tahoe, the commercial Vans, and 1/4 ton through 3/4 ton pickups. With those vehicles you don't typically see people towing much over 10,000lbs, which is well within the capability of this engine. With such shared usage among platforms it could really help to keep the cost of this engine down, thereby making it even more appealing for the average buyer versus the over $8,000 6.6L diesel option. Plus, it doesn't require the Allison transmission or a slight body lift to fit like the larger engine, again making it a more financially feasible option.

      Go for it Gm!
      • 4 Years Ago
      put this engine in the canyon too please!!! they fit in the V8 gas now so this would fit too. 4,000 lb 4x4 diesel rocket!! mileage would probly be double what i get off my '02 ZR2 as well . I'd order one tommorrow if they did it , even if they dont lose that ugly grill.. ( please make the front of these trucks cooler looking if youre reading this GM , losing the turn signal over the headlamp would be a great 1st step)
      • 5 Years Ago
      OK GM.......Your customers are TELLING YOU WHAT THEY WANT.....BUILD IT !!!!! I bleed GM blue, and always will, but there was always a communications problem within the company. Listen to your customers, and the profits will follow !!!!!
      • 5 Years Ago
      I think GM needs to put a dura max diesel in their light duty trucks. If the HDs get over 25 mpg, then, the LDs should get a better miles per gallon.
      Considering the new fuel mileage laws that are coming and soon. Light Duty diesels are a GREAT idea. GMC/Chevrolet could be the first on the market with these products and could improve their bottom line. Dodge and Ford should reconsider as well. Want to sell more trucks? Make them more fuel efficient.

      • 5 Years Ago
      Ya know...this engine would also fits in the engine bay of the CTS. All they have to do is use the CTS-V bulged hood.

      Is it just me, or does the idea of a CTS-D wagon with 500+ ft/lb of torque make anyone else giggle a little?
      • 5 Years Ago
      In addition to 1/2 ton pickups... offer it in the SUVs as well
        • 5 Years Ago
        Absolutely... We tow a travel trailer camping throughout the summer with our SUV, and I would immediately get a diesel powered mid/full-size SUV that gets milage north of mid 20's
        • 5 Years Ago
        Of course, I'd bet that 25 mpg number they are quoting is highway mileage, not combined. Still impressive for a full-size pickup, though.
        • 5 Years Ago
        Exactly! My '03 V8 4Runner gets a combined 16 mpg on my mostly city, part highway commute. Build a true body-on-frame SUV with 4WD and a two-speed transfer case that gets a real-world 25 mpg and I'd be all over it.
      • 5 Years Ago
      The reason no one is putting diesel in 1/2 ton and SUV is the exhaust emission standard for light trucks are a lot tighter than 3/4 and 1ton truck
      • 5 Years Ago
      Totally agree with ALEX. If they apply this engine to the 1/2 ton chasis, the first mfgr. wins bigtime. Hell, without a headwind @ 75-85 mph my Escalade gets 16 mpg hwy, and wouldn't I and others love to see even the lower 20's with this sweet motor ?
      • 5 Years Ago
      Build it and I will buy it. I've been holding out for years to see a 1/2 diesel come to market.
      • 5 Years Ago
      surburban/4.5 diesel.......i'm on board....
      • 5 Years Ago
      This would be the smartest thing they could do- There are plenty of operators out there who run lots of miles, need the load capacity of an HD, but have little or no use for the huge tow capacity the big Duramax offers. The 610 Van would be another great candidate, as it currently uses a low power version of the Duramax 6.6, which adds $12k to the price of the van. The 4.5 is a better fit, weighs less and could return much better fuel savings. The 6L90 Transmission is a good match for the smaller engine. It weighs and costs less, too.
      Putting the 4.5 diesel in only the 1500 would likely not net sufficient volume for recovering the investment (this is also a big factor why Toyota and Nissan shelved their diesel plans). The combined volume would be high enough, and the remaining 6.6 Duramax numbers would also still make sense. The Urea system for the HD trucks is in production, and could quickly be adapted to the smaller engine.
      • 5 Years Ago
      Jobu- got me there. I knew DI was being rolled out, but I personally find that segment a little un-interesting. Perhaps some transmission retuning could help, but end of the story is that these are just very heavy lumps. Low-pressure turbo would work nice to fatten up the torque curve.
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