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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

Frustrated GM investors ask what more Mary Barra can do

DETROIT — General Motors Co Chief Executive Mary Barra has transformed the No. 1 U.S. automaker in her almost five years in charge, but that is still not enough to satisfy investors. Ahead of third-quarter results due on Oct. 31, GM shares are trading about 6 percent below the $33 per share price at which they launched in 2010 in a post-bankruptcy initial public offering. The Detroit carmaker's stock is down 22 percent since Barra took over in January 2014. After hitting an all-time high of $46.48 on Oct. 24, 2017, the shares have declined 33 percent. In the same period, the Standard & Poor's 500 index has climbed 7.8 percent. Several shareholders contacted by Reuters said GM could face a third major action by activist shareholders in less than four years if the share price does not improve. "I've been expecting it," said John Levin, chairman of Levin Capital Strategies. "It just seems a tempting morsel to somebody." Levin's firm owns more than seven million GM shares. Barra has guided the company through the settlement of a federal criminal probe of a mishandled safety recall, sold off money-losing European operations, and returned $25 billion to shareholders through dividends and stock buybacks from 2012 through 2017. GM declined to comment for this story, but the company's executives privately express frustration with the market's reluctance to see it as anything more than a manufacturer tied mainly to auto market sales cycles. GM's profitable North American truck and SUV business and its money-making China operations are valued at just $14 billion, excluding the value of GM's stake in its $14.6 billion Cruise automated vehicle business and its cash reserves from its $44 billion market capitalization. The recent slump in the Chinese market, GM's largest, and plateauing U.S. demand are ratcheting up the pressure. GM is one of the few global automakers without a founding family or a government to serve as a bulwark against corporate raiders. In 2015, a group led by investor Harry Wilson pressed GM to launch a $5 billion share buyback, and commit to what is now an $18 billion ceiling on the level of cash the company would hold. In 2017, GM fended off a call by hedge fund manager David Einhorn to split its common stock shares into two classes. Einhorn, whose firm still owned more than 21 million shares at the end of June, declined to comment about GM's stock price. Other investors said there were no clear alternatives to Barra's approach.

2016 Chevy Volt rated at 106 MPGe, 53 miles of pure EV range

Following a string of rumors, Chevrolet and the Environmental Protection Agency have released official fuel economy numbers for the second-generation Volt. As was reported earlier today, the new and improved hybrid will cover 53 miles on pure electric power. As Chevy tells it, first-gen Volt owners cover about 80 percent of their mileage on EV power alone, so the 40-percent increase from the second-gen should lead to an even bigger reduction in gas-powered Volt mileage. Chevy expects some 90 percent of mileage to come from a plug with its new 2016 model. This newfound EV range comes thanks to the 2016 Volt's 18.4-kilowatt hour lithium-ion battery. Rated at 106 MPGe by the feds – exactly what was promised by a June leak – the 2016 Volt improves nicely on the current model's 17.1-kWh, 98-MPGe battery back. There's also a marked improvement when relying on the gas-powered on-board generator. The 1.5-liter, four-cylinder engine will happily run on regular fuel and return a still-impressive 42 miles per gallon combined rating once the battery's state of charge is depleted. Expect the freeway to cruise to be even better, although Chevy isn't ready to say by how much. Fully charged and with a full tank, drivers should expect to cover 420 miles, a 40-mile improvement over the current model. Scroll down for the official press release from Chevrolet Related Video: The Results Are In: More Range for the 2016 Volt EPA-estimated pure electric range is 53 miles DETROIT – The 2016 Volt is engineered to offer customers more of what they want: range, range and more range. The Volt's all-new second-generation Voltec extended range electric propulsion system delivers 53 miles of pure EV range, based on EPA testing. That is nearly a 40-percent improvement over the first generation Volt. Chevrolet expects many next-generation Volt owners will use power solely from their battery for more than 90 percent of trips. Today, Volt owners use battery power on 80 percent of their trips. This means that the average Volt owner may expect to travel well over 1,000 miles between gas fill ups, if they charge regularly. For the first 53 miles, the Volt can drive gas and tailpipe-emissions free using a full charge of electricity stored in its new 18.4-kWh lithium-ion battery, which is rated at a combined 106 MPGe, or gasoline equivalent. When the Volt's battery runs low, a gas-powered generator seamlessly operates to extend the driving range for a total of 420 miles on a full tank.