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GM patent reveals new two-stage turbocharger

Modern turbochargers may be some of the best ever made, but performance is something that engineers are always trying to improve. According to GM Inside News, General Motors (GM) is hoping to alleviate some of the negative aspects of a two-stage turbocharger setup with a newly-patented design. The patent, that was filed on May 19, 2016, reveals a clever bypass system that allows the engine, a four-cylinder unit, to optimize both the low-pressure and high-pressure inlets for its respective functions. According to the filing, a conventional two-stage turbocharger setup is engineered to allow both turbines to operate simultaneously at low and mid engine speeds. At high engine speeds, only the low-pressure turbine works. The setup can't isolate either the low or high pressure side, which can impair low-end performance. GM's new two-stage turbocharger setup looks to eliminate this by linking the high-pressure turbo to the exhaust manifold through the high-pressure inlet duct. The low-pressure turbo is attached to the high-pressure turbo by a low-pressure inlet duct, which is linked to a connecting channel. A single actuator that is housed in the exhaust manifold creates a bypass that can opens the high-pressure inlet or close the connecting channel. Depending on what the engine load and speed is, the ECU guides the actuator—a single rotating spindle with discs corresponding to flanges on the high and low pressure sides—to isolate one of the two turbos. Isolating the turbos allow the respective inlets to be engineered for the best possible fluid dynamic performance. The setup should increase performance and decrease lag. There's no word on what car this setup will make an appearance on, but it will most likely be used in premium vehicles before trickling down to the rest of GM's vehicles. Related Video: News Source: GM Inside News, AutoGuide via GM Authority Cadillac Chevrolet GM Technology Sedan turbo patent engine turbocharging

GM files for Z71 Trail Boss trademark

Try as they might to keep their plans a secret, automakers have their hands tipped through a variety of methods – be they through loose lips, spy shots or patent and trademark applications. That's how we know, in this instance, that General Motors is working on (or at least considering) an off-road machine wearing the name Z71 Trail Boss – the name which our compatriots at AutoGuide.com tell us that GM has registered for use on light-duty trucks. Now if that alphanumeric designator sounds familiar, it should. GM has long used it to designate the off-road packages on many of its body-on-frame trucks from Chevy and GMC. These days you can order a Z71 package on the Chevy Colorado, Silverado, Tahoe and Suburban and on the GMC Canyon, Sierra and Yukon. The package typically includes components like a beefed-up suspension bits, high-capacity air cleaner and underbody protection plates. The Trail Boss designator would seem to suggest something further reaching than a suspension package, though. Just what it would entail we don't know; minds immediately start running toward Chevy or GMC going after the Ford F-150 Raptor, but we'll likely be looking at something closer to the Trailhawk packages Jeep offers on the likes of the Renegade and Cherokee. Featured Gallery 2015 Chevrolet Tahoe Z71 View 16 Photos News Source: AutoGuide.comImage Credit: Chevrolet Chevrolet GM GMC Truck SUV Off-Road Vehicles patent trademark

GM issues stop-sale for 3 SUVs over incorrect MPG rating

This week, GM sent a memo to Chevy, GMC, and Buick dealers to tell them to stop selling three SUVS. The 2016 Chevy Traverse, the GMC Acadia, and the Buick Enclave all have EPA window stickers that show higher fuel economy ratings than the vehicles actually have. Unlike other recent – and very public – fuel economy ratings problems from VW and Mitsubishi, it doesn't seem like GM did anything wrong with the testing for these vehicles, it just misprinted the labels. New labels are being printed and should arrive at dealerships this weekend and early next week. After that, the SUVs will be able to be sold and delivered again. The official fuel economy rating for the three SUVs are all the same. The correct numbers for the all-wheel drive versions are 17 miles per gallon combined, 15 city, and 22 highway. The stickers say the SUVs get 17/24/19. The front-wheel driver models were also incorrectly labeled, and the total number of affected vehicles is 59,823. In the memo, GM said the problem was caused by an "inadvertent error," Automotive News says. GM is working with the EPA to solve the issue. We have asked GM for a comment on the mistake and will update this post if we hear back. Related Gallery 2013 GMC Acadia View 16 Photos News Source: Automotive News – sub. req. Government/Legal Green Buick Chevrolet GM GMC Fuel Efficiency mpg gmc acadia chevy traverse