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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.

2014 Chevrolet SS makes its live debut

Chevrolet showed off the new 2014 SS in an airport hangar last night, its first rear-wheel-drive performance sedan in the US since the Impala SS from 1997. We'll have more to say about the SS later today, but this is the sedan that Chevrolet sees as the final piece in restoring its performance credentials. For those of you looking for a manual transmission, however, that wish will go unfulfilled - at least for now: the only two options buyers will have are the color and whether or not they want a sunroof.
We'll work on getting some more angles (in better light) today at Daytona International Speedway, but with fans seeing the car for the first time, we don't hold out much luck of getting a clear shot. So for now, enjoy the high-res gallery above.

GM applies for LT5, LTX trademarks... are new small block variants coming?

Recently discovered General Motors trademark applications for LT4, LT5, LT88 and LTX have observers wondering what kind of high-performance offerings could be on their way. A new LT4 would mark a return of the engine designation first used on the Corvette Grand Sport, SLP Pontiac Firehawk and SLP Chevrolet Camaro SS from 1996 and 1997. Supposition at Corvette Forum - which provided advance intel on the C7 like these leaked images - believes a new LT4 could go into the high-performance trim of the next-gen, 2015 Camaro that would be more powerful than the 580-horsepower Camaro ZL1.
Seeing an LT5 again would also be déjà vu - in its former life it was a 5.7-liter V8 for the C4 Corvette ZR-1 from 1990-1994 designed by Lotus, producing from 370 hp to 405 hp. A mix of rumor and hope is that the new LT5 will be a supercharged evolution of the 6.2-liter LT1 (pictured) placed in the new C7 Corvette, and that it will go into the C7 version of the ZR1 pumping out something like 700 hp.
The LTX trademark is, as with that last letter, a complete mystery. If the "X" isn't a generic way to denote the whole LT family, it's wondered if it LTX could refer to a crate motor offering like the LSX.