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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.

Engine block heater issues force GM to recall 324,226 diesel heavy duty trucks

General Motors has issued a recall on 324,226 diesel heavy duty trucks that could be susceptible to short circuits, and consequently, potential fire. The recall affects several models of heavy duty Chevrolet Silverados and GMC Sierras with optional engine block heaters. GM is recalling seven different truck models spread across three years. The recall affects the 2017-2019 Chevrolet Silverado 2500HD, 2017-2019 Silverado 3500HD, 2019 Silverado 4500HD, 2019 Silverado 5500HD, and 2019 Silverado 6500HD, plus the 2017-2019 GMC Sierra 2500HD and 2017-2019 Sierra 3500HD. Specifically, it includes these models with the 6.6-liter Duramax diesel engines and the optional engine block heater. The recall technically deals not with the engine block heater itself, but the way it is connected. According to NHTSA campaign No. 19V328000, the engine block heater cord or the terminals that link the cord to the heater could short circuit. A short circuit could potentially damage engine components and result in a fire. According to The Detroit News, 19 fires have been reported but nobody has been injured. GM has yet to figure out a fix, and thus has not yet released a notification schedule for affected customers. If you believe your vehicle is part of the recall, contact GM customer service at 1-586-596-1733 and use reference number N182206310.

GM issues stop-delivery for 2015 Chevrolet Colorado and GMC Canyon

General Motors is issuing a stop-delivery order for its latest midsize pickups, the 2015 Chevrolet Colorado and GMC Canyon, because the driver's side airbag might not be wired correctly. The total number of vehicles affected is still being determined.
According to the statement from GM, the problem, "affects the vehicles' two-stage airbag system by reversing the deployment sequence and disrupting the deployment timing of the driver airbag stages." That means in an accident the bag may not work correctly.
Most of the affected trucks are still on the assembly line, in transit or unsold at dealers, says GM. Until a way to repair the problem is found, customer deliveries are stopped. However, "a small number" of them are in the possession of buyers. GM is contacting these people by phone and by FedEx letter to have the vehicles returned to dealers. In the meantime, they'll be given a loaner to drive.