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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.

Canada opens probe into 250,000 GM pickups, SUVs over brake performance

Transport Canada, the auto safety regulator, has opened a probe into braking issues in nearly 250,000 General Motors full-size pickups and SUVs after U.S. officials launched a similar probe last year, the agency said on its website. The U.S. National Highway Traffic Safety Administration (NHTSA) in November into 2.73 million U.S. 2014-2016 model year SUVs and pickups after receiving 487 reports of hard brake pedal effort accompanied by extended stopping distance that were attributed to deterioration of the engine-driven brake assist vacuum pump. Transport Canada's probe covers 249,700 2015 through 2017 model year vehicles including the Cadillac Escalade, Chevrolet Suburban, Chevrolet Tahoe and GMC Yukon as well as 2014-2017 Chevrolet Silverado LD and GMC Sierra LD vehicles. The U.S. agency said it had reports of nine incidents of vehicles incurring damage as a result of colliding with another vehicle or fixed object at low speeds and reports of two injuries. NHTSA said if the pump fails to operate, the amount of brake power assist can be significantly reduced, extending vehicle stopping distance. The NHTSA sent GM an information request in a Feb. 7 letter. A GM spokesman said he had no update on the investigation. Reporting by David Shepardson; editing by Jonathan Oatis

Porsche wins the 2015 24 Hours of Le Mans

The question going into this year's 24 Hours of Le Mans was whether or not the Porsche 919 Hybrid would be able to combine its qualifying pace with race reliability. After battling neck-and-neck with Audi's R18 for most of the race, the answer is a resounding yes. Not only did Porsche drivers climb the first two spots on the podium, they did so without any major mishaps on track. This win is the first overall trophy for Porsche since 1998. Audi previously won the last five races, and 13 of the last 15. Corvette also returned to the winner's circle, with the No. 64 C7.R taking winning the GTE Pro division. The victory is the first class win for Corvette since 2011. KCMG won the LMP2 class in ninth overall. With 45 minutes to go the No. 98 Aston Martin crashed out of first place in GTE Amateur, giving the class win to SMP Racing's Ferrari and second place to the Patrick Dempsey Racing Porsche 911 RSR. For the full list of official results, click here. The GTE Pro class proved to be just as exciting as the P1 class, with a four-way battle for first after four hours into the race. For most of the race, the battle at the top went back and forth between the two German manufacturers. An tire puncture in the No. 7 Audi gave up the lead to Porsche, and moments later a crash forced the No. 8 into the garage. But a three-minute replacement of the front and rear bodywork kept the Audi in contention. As the race wore into the night, Porsche maintained a slightly faster pace than Audi. Nick Tandy took the lead on Lap 253 early Sunday morning, and car No. 19 never gave up the top position. The win is the first for all three drivers of the No. 19 – Nico Hulkenberg, Earl Bamber, and Nick Tandy. A lap behind in second was the No. 17 Porsche. The Audis fought reliability problems late in the race but still finished third with the No. 7 R18. The GTE Pro class proved to be just as exciting as the P1 class, with a four-way battle for first after four hours into the race. As the Aston Martin cars dropped away, the lone Corvette Racing entry took over, followed by a charging AF Corse team Ferrari 458 Italia. The Corvette and Ferrari continued to trade places in the final hours until gearbox trouble forced the No. 51 Ferrari out of contention. It was eventually passed by the other AF Corse car, No. 71. Nissan experienced all the pain of a first-year effort with its front-wheel-drive GT-R LM Nismo.