2003 Gmc Sierra 3500 Duramax Extended Cab Flat Bed Dually 2wd 122k Miles on 2040-cars

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GM exploring ways to raise half-ton Duramax diesel tow rating

Lots of truck owners cheered when GM announced fuel economy numbers for the 2020 Chevrolet Silverado with the 3.0-liter Duramax diesel inline-six. Even after Ram let loose its EPA mileage ratings for the 2020 Ram 1500 EcoDiesel, the Chevy oil-burner still took the trophy. The victory was years in the making, GM engineers spending an entire four-year development cycle refining the LM2 Duramax to increase mileage. The tradeoff, as well all know by now, is towing; the Duramax in half-ton duty pulls a maximum 9,300 pounds in the Silverado. Rivals across town can do more, the Ford F-150 PowerStroke rated at 11,500, the Ram 1500 EcoDiesel game to pull 12,560. GM engineer John Barta told Muscle Cars & Trucks that more hauling chops could be on the way, explaining, "We’re actually looking at upgrading some of the materials around (the engine bay) to see if we can maybe raise our tow rating." Engine bay materials are at issue due to thermal complexities underhood. John Barta, GM's assistant chief engineer of diesel engine controls, said the Duramax's inline-six configuration allowed engineers to get emissions hardware like the combined selective catalytic reduction, diesel oxidation catalysts, and diesel particulate filter unit closer to the engine, where it heats up quicker, getting emissions down quicker. But that filter puts another heat source in those confines, enforcing a cap on the tow rating to keep the engine and other systems from overheating. "If you look under the hood," he said, "youÂ’ll see a significant amount of silver ‘moon tapeÂ’ around to make sure things arenÂ’t getting overheatedÂ… if we were to go up in higher towing, which we can, we start impacting the possibility of deteriorating some of the components.” There isn't much space for more grille, so swapping for a better grade of "moon tape" or a different kind of material could reduce engine bay heat, extracting a higher tow rating in the process.  It's important to note a point Barta's been making for months about the Duramax figures, though. "Even though itÂ’s nice to brag about big numbers, in reality, light duty customers are not towing that large with their trucks," and, "We do know that (95 percent) of our light duty customers donÂ’t tow over 9,000 pounds." On our First Drive of the 2020 Silverado diesel we called out the tow rating, but emphasized that the Chevy and GMC have more important challenges to overcome.

Diesel Power finds the ultimate modified oil-burner

For nine years, Diesel Power magazine has run the Diesel Power Challenge, this year's grindfest being "a week-long torture test that features seven events, nine trucks, 8,000 horsepower, and nearly 15,000 pound-feet of torque." The road to being crowned "the most powerful truck" starts with a dyno run, and then continues through the completion of a CDL-style obstacle course, an eighth-of-a-mile drag race while towing a 10,000-pound trailer, a quarter-mile drag race without a trailer, a fuel economy test in the mountains and finally a sled-pulling test through a 300-foot-long packed-mud pit.
What kind of trucks get into such a fight? Last year's winner, for instance - who upgraded his truck this year to prove he didn't "luck into the win" - drives a 2008 Ford F-250 Super Duty with a 6.4-liter Power Stroke V8 upgraded with a custom intake, Elite Diesel triple turbos and a two-stage nitrous system. Another competitor has a 2005 Dodge Ram 2500 powered by a 5.9-liter Cummins inline-six, upgraded with Garrett turbos, dual-stage nitrous, a seven-inch exhaust stack and twin fans built into the bed to cool the Sun Coast Omega transmission. The numbers on that truck: 1,255 horsepower, and 2,063 pound-feet of torque at the wheels. Naturally, as the image above might suggest, things don't always end well.
You'll find all five videos covering this years challenge below. A scene in the dyno video sums it all up perfectly: a competitor leaves his nitrous on too long and the crew is treated to some ominous poppings, he leans out the window, throws both hands up and shouts, "Amer'ca!"

GM may have teased a whole group of electric vehicles

During GM's big CES press conference, the automaker highlighted a number of its upcoming electric car-related projects from delivery vans to the upcoming flagship Cadillac Celestiq. In the middle of it all, a collection of mystery cars sat in the background behind speakers. They were in the dark, lit only with their running lights, and while it's possible they're just generic filler cars or concepts, we think they could be future products. Our best shot of the cars together is shown above, and we can pretty easily identify three of the vehicles. In the center is obviously the GMC Hummer EV. On either side of it are Cadillacs. To the left seems to be the Lyriq crossover, and to the right is the Celestiq sedan. Two of these cars have production dates, and the third has been confirmed for eventual production, just without timing. This is why we think the rest of the cars are upcoming models. The next most easily identified car is on the near right behind the Cadillac Celestiq. It very clearly has a Chevy bowtie illuminated in the running lights. And looking closely, it appears to be a pickup truck. It's difficult to make out anything more than that. The nose does look a bit more rounded and swept back than the brick-like designs of the Silverado truck line. That also squares with what seemed to be the upcoming truck that appeared in the background of yet another GM presentation. GM previously said this electric Chevy truck will be a full-size model with up to 400 miles of range. That leaves us with three more mysterious models. Over to the left behind the Cadillac Lyriq are what appear to be a pair of crossovers. The one on the far left looks low, curvy, and possibly with a fastback roof. The one on the right is taller, boxier, and probably more of a full-size people hauler. It's hard to say much more beyond that. They could be new electric Buicks, which would fit in nicely with that brand's crossover portfolio, and would likely be highly successful in China, where Buicks, crossovers and electric cars are all rather hot commodities. As for the mystery car on the far right, it's quite a puzzle. We can at least rule out Buick and Cadillac, and GMC since it's definitely a car, and a rather small one compared with the other cars on display. That leaves Chevy, and possibly the autonomous division Cruise. We're leaning toward it being a Chevy, since the first Cruise vehicle is going to be a boxy pod of sorts.