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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.

Driving the Toyota Supra, Honda Passport and BMW 3 Series | Autoblog Podcast #582

In this week's Autoblog Podcast, Editor-in-Chief Greg Migliore is joined by Green Editor John Beltz Snyder and West Coast Editor James Riswick. First, they talk about the cars they've been driving, including the Honda Passport, BMW 330i and Audi RS5. They follow up with notes about driving the Toyota Supra and 86, and whether Toyota's new sports car strategy makes sense. Then they discuss the news, including the Ferrari SF90 Stradale plug-in hybrid, a possible Renault-FCA merger, death rumors for the Jaguar XJ and thoughts on the upcoming Chevy Trailblazer. Autoblog Podcast #582 Get The Podcast iTunes – Subscribe to the Autoblog Podcast in iTunes RSS – Add the Autoblog Podcast feed to your RSS aggregator MP3 – Download the MP3 directly Rundown Cars we're driving: 2019 Honda Passport 2019 BMW 330i 2019 Audi RS5 Sportback Toyota Supra, 86 and the company's sports car strategy In the news: Ferrari SF90 Stradale FCA and Renault Jaguar XJ going away? Chevy Trailblazer Feedback Email – Podcast@Autoblog.com Review the show on iTunes Related Video:

2016 Chevrolet Colorado Diesel First Drive [w/video]

The first thing you notice inside the diesel Chevy Colorado is that it's quiet. Almost too quiet. A lot has been done to quell noise and vibration with this new powertrain, and it shows – or rather, doesn't. There's some characteristic diesel clatter at idle, but even then it's distant and practically disappears as you start moving down the road. At full throttle, when the engine is at its noisiest, the sound isn't particularly diesel-like, just a pleasant intake breath. The accompanying smoothness is almost eerie. When we ask where all the noise went, Chevy's engineers, marketing guys, and PR reps all explain that this refinement is what Americans want. We're still not sure. This is a truck, after all, and the diesel pickup customer is different from the guy buying a diesel Cruze for his highway commute. Chevy contends that they're also not the same as the buyer of a Silverado HD. Although this 2.8-liter Duramax four-cylinder has been in service elsewhere around the globe, its first US application is in the Colorado and its GMC Canyon twin. The engine puts out 181 horsepower and 369 pound-feet of torque, and it does so unobtrusively as a result of a lot of modifications for our market. To keep normal diesel sensations out of the cabin, the intake and oil pan both get acoustic treatments. A new, thicker material is used for firewall sound deadening. Redesigned balance shafts have tighter tolerances to increase smoothness. The diesel powertrain is smoother than the Colorado's gasoline V6. One of the more interesting and certainly unexpected vibration-reduction changes is a special torque converter from German supplier LuK equipped with a centrifugal pendulum absorber. This pendulum spreads from the center of the torque converter as engine speed increases and is tuned to absorb the four-cylinder's second-order vibrations, not just those in a narrow frequency band. It does an admirable job, especially considering the engine's biggish, 0.7-liter cylinders, which lead to bigger vibrations. The result is a powertrain that's smoother than GM's (not particularly smooth) corporate V6, which is available in the standard Colorado. It's quieter than a Cruze diesel and even out-softens some gas direct-injection engines on the market. Paradoxically, it may be the most refined of all of the Colorados. No vibration comes through the steering wheel, pedals, floorboards, or even the rearview mirror. But you can tell it's a diesel when you hit the throttle.