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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.

Silverado HD, Touareg V10 TDI face off in diesel tug-of-war

A couple weeks ago, we watched a Chevrolet Silverado get dominated by a Dodge Ram Heavy Duty in a fullsize pickup tug-of-war, but in that truck's defense, Chevy's Vortec gas engine was no match for the torquey Cummins turbo diesel. For our next round of vehicular tug-of-war, a Duramax-powered Silverado HD takes on Volkswagen Touareg V10 TDI.
Now, on paper, putting the Duramax V8's 365 horsepower and 660 pound-feet of torque up against the V10's 310 hp and 553 lb-ft looks like an easy win for the Bowtie, but unfortunately, this battle has a similar result as the Dodge versus Chevy video, with the Silverado smoking its tires trying to move forward as it gets pulled backwards. Put another way: YouTube 2, Chevy Silverado 0.
It just goes to show, though, that big tires, bolt-on fender flares and goofy smoke stacks don't improve your towing abilities. Besides, what did the Silverado driver expect when the Touareg V10 TDI has towed a Boeing 747 in the past?

GM delays 3.0-liter Duramax diesel in Silverado and Sierra pickups

Stricter testing protocols around the world are making it harder for automakers to predict launch timelines. GM is the latest to get caught in emissions nettles, the Detroit carmaker forced to delay the launch of its new Duramax 3.0-liter inline-six diesel for the Chevrolet Silverado 1500 and GMC Sierra 1500. That's what company reps told dealers in a memo seen by Automotive News this week. Dealers and buyers had been promised the Flint, Mich.-built oil-burner in early 2019, but AN wrote that the EPA certification hiccup has turned into a "slight delay." A GM spokesman told Motor1, "[We] did not attribute [the delay] to a single entity, as the truth is this is a collaborative effort between GM and several government entities. We will make the 2020MY Duramax available for dealers orders soon, and expect to deliver the first trucks to customers soon after emissions testing is complete." We know the new 3.0-liter Duramax diesel has 277 horsepower and 460 pound-feet of torque, outdoing Ford's 3.0-liter PowerStroke diesel by 27 hp and 20 lb-ft. But without final EPA paperwork, GM can't release the numbers that will show how the two engines stack up when considering fuel economy and tow ratings. The certification process has been sticky for a few other makers of late, especially since the Volkswagen Group situation in 2015. BMW had to delay the launch of four diesel models in 2016 over EPA testing. The new Ram 1500 dribbled out in a trickle last year for reasons thought to deal with EPA testing, coming as it did a year after the EPA investigated Ram's EcoDiesel engines in 2017 and 2018. More recently, WLTP testing in Europe caught out just about every automaker over there. Since we're almost halfway through 2019, the delay until the 2020 model year is only a few months. Still, GM told dealers to cancel any orders for the engine for this model year. Dealers will need to resubmit the orders once opening begins, but GM hasn't said when production will begin other than "soon." The company said that it will offer 2020-model-year replacement vehicles to customers and dealers. If prices hold into the next model year, the 2020 Silverado 1500 and Sierra 1500 with the inline-six diesel will come at a $3,890 premium over the 2.7-liter turbo four-cylinder, and a $2,495 premium over the 5.3-liter V8.