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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.

NHTSA upgrades probe into 1.7 million GM vehicles over wiper failures

WASHINGTON — The U.S. National Highway Traffic Safety Administration (NHTSA) said Tuesday it is upgrading an investigation into 1.7 million General Motors vehicles for windshield wiper failures. The auto safety agency opened the probe in November 2018 to see if GM needed to expand a 2016 recall of 2013 model year Chevrolet Equinox and GMC Terrain SUVs to cover additional vehicles. The engineering analysis probe covers 2010-2012 and 2014-2016 Equinox and Terrain vehicles. NHTSA could demand a recall after it completes the probe. NHTSA said it has reviewed 1,900 complaints and reports related to the issue in the 1.7 million vehicles. NHTSA said it has seen elevated failure rates in the 1.7 million vehicles, even though GM said the recalled vehicles have "double the warranty rate and five times the complaint rate." GM said it will "fully cooperate to support their investigation. We do not believe these windshield washer systems are defective." The wiper failures that prompted the 2016 recall were attributed to water and debris intrusion into the windshield wiper assembly ball joints, leading to excessive wear and eventual detachment of the ball joint. GM said it was installing an improved windshield wiper motor and transmission assembly and relocating a drain hole at the base of the windshield. Related Video:

2020 Chevy Silverado HD vs. 2019 Ram, Ford heavy duty trucks: How they compare on paper

Last year was all about the latest in light-duty full-size pickup trucks, so this year, Ram, Ford and Chevy are launching the heavy-duty variants. The first out of the gate is the redesigned 2019 Ram 2500 and 3500 HD, and Ram dropped all the pertinent specs with the reveal. Chevy followed with the new Silverado HD in Chicago, and Ford revealed updates to the Super Duty at the same show. Ford hasn't released details on output, payload capacity, towing capacity or pricing for the updated Super Duty. As such, we'll be comparing the current Super Duty with the all-new Silverado HD and Ram HD. Both Chevy and Ram have revealed full specs for each of their respective trucks, leaving out only pricing, which we've estimated based on the outgoing models. You can see the raw details in the chart below, followed by extra information and analysis. Some things to keep in mind: These specifications cover all versions of the Ram HD, Silverado HD and Super Duty, such as 2500 and 3500 models, and all the way up to F-450. Specifications can vary widely based on engine, drivetrain, cab and bed configurations, so be sure to take a close look at the specific model you're interested in when you get particularly serious about buying. And of course, be sure to check out our car comparison tool if you'd like to look at other trucks on the market. Engines and drivetrains All three of these trucks offer gasoline and diesel engines, but only the Ram has two versions of the diesel. Starting with gas engines, Ram's 6.4-liter V8 has the power advantage with 25 more horsepower than the next-most-potent Super Duty, but the new Silverado HD's 6.6-liter V8 takes the torque crown at 464 pound-feet, nearly 35 more than the other two gas engines. The Ram is also the only one to pair an eight-speed automatic with the gas engine, whereas the Ford and Chevy make do with a six-speed. With diesel engines, horsepower is a weak point for the Ram. The Ram's entry-level turbo 6.7-liter inline-six is the weakest, as the only one with under 900 pound-feet of torque and under 400 horsepower. Even the high-output version only makes 400 horsepower, while the Chevy makes 445 and the Ford 450. But the tables turn with torque, as the Ram makes a best-in-class 1,000 pound-feet followed by the Ford's 935 and the Chevy's 910. Both the Ram and the current Super Duty diesels each get a six-speed automatic, but the new Silverado HD's diesel gets a 10-speed unit.