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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.

Watch a 2015 Corvette Z06 run the quarter in 11.7 seconds

We're not writing about this because it's an amazing run, we're writing about it because it appears to be the first run. Someone took a 2015 Corvette Z06 to Royal Purple Raceway in Baytown, Texas and blasted it down through the quarter mile. It's still wearing the dealer number in wax pen on the windshield and dealer plates, so this example is fresh from the mold. It's also a seven-speed manual. General Motors said the row-your-own Z06 can do the 'strip in 11.2 seconds, and they undoubtedly had a professional driver and more than one run to set that time. To have Just Some Guy show up at the raceway and do an 11.7 at 120.54 mph on his first run means we expect good things to come as Z06s get delivered to their owners. Check out the run in the video.

2020 Chevy Trax and Buick Encore spied testing

We just recently saw a little crossover SUV from General Motors being tested, and we weren't positive what brand it belonged to. We narrowed it down to Chevy or GMC, but we're feeling more confident that it's a GMC now, since both the next generation Chevy Trax and Buick Encore subcompact crossover SUVs have been spied testing together. Of the two, the Chevy has the more radically different sheet metal. It ditches the somewhat frumpy, lumpy shape of the current Trax for a body inspired by the bigger Chevy Blazer. The roofline has sharp corners, and the hood is wide and flat. The front fascia, though obscured, shows the most connection to the bigger crossover. It has the same split headlight configuration, and it looks as though the grille takes up a sizable section of the fascia. View 7 Photos The Buick Encore on the other hand looks evolutionary in design. The body still has plenty of curves, and the distinctive, sharply rising window sill are all hallmarks of the current Encore design. The headlights and grille are similar, too, though the grille appears to be slightly updated to fit in with the Enclave and Regal. It's understandable that Buick might want to play it safe with the new Encore, since the model is Buick's best seller, selling about 23,000 units in the last quarter, nearly twice that of the next best performer, the Enclave. Since this is the first time we've seen these little crossovers, we expect it will still be a year or two before we get to see them fully revealed. They will probably continue to use small-displacement turbocharged four-cylinder engines with either front- or all-wheel drive. Related Video: