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Infiniti's new VC-T changes the rules of small turbocharged engines

The upcoming Infiniti QX50 crossover does not get our pulse racing, no matter how shapely the QX Sport Inspiration concept that previews it may be. No midsize SUV does, to be fair. But it has something special under the hood – the world's first production variable-compression-ratio engine. That means the QX50's 2.0-liter turbo four, which makes 268 horsepower and 288 pound-feet of torque, will have up to 27 percent better fuel economy. Here's how it works. The trend of moving to smaller, turbocharged engines carries with it one big falsehood. Under low load when the turbo isn't needed, these engines are less efficient than an equivalent engine without a turbo because of the low compression ratio the turbo requires. That is, if you never need the extra power, you're wasting fuel. Turbocharged (and supercharged) engines use a lower compression ratio to prevent detonation. When you force extra air in a cylinder and mix it with fuel, it's more likely to prematurely go boom. Lowering the compression ratio prevents this problem, but it's less efficient. Infiniti's VC-T promises the best of both worlds, with a compression ratio that ranges from 8.0:1 for high-power turbo needs to a 14.0:1 ratio for fuel-sipping efficiency. At its heart the VC-T engine is a simple idea, but it's complicated to explain. Consider yourself warned. The photo below from Infiniti serves as a good visual overview. For the truly nerdy, this patent application covers the mechanical concept. Instead of having the pistons connected to the crankshaft, Infiniti's engine has a pivot arm with a connection on each end. One end connects to the piston, the other connects to a second lower shaft, which is controlled by an actuator arm. At any given time the engine's pistons move up and down according to the lobes on the crankshaft. But the actuator arm can change the angle of the pivot arm up and down. That is, the pistons still move in the same motion with the same stroke, but phase the entire stroke up or down. Move the pivot up and there's less room at the top, which means a higher compression ratio. Move the pivot down and the compression ratio goes down, too. As an added bonus, the lower shaft eliminates the need for counter-rotating balance shafts. Infiniti says this system works constantly and can vary the compression ratio to any number between 8:1 and 14:1. It also uses electronic variable valve timing on the intake valves to switch into Atkinson-cycle combustion for greater efficiency.

Weekly Recap: Ferrari, Ford and Porsche power up for Geneva

Monday was Groundhog Day. Tuesday, apparently, was Sports Car Day. The Ferrari 488 GTB, the Ford Focus RS and the Porsche Cayman GT4 all debuted within hours of each other ahead of their rollouts at the Geneva Motor Show. Three sporty machines, three vastly different approaches – and a lot of implications for enthusiasts. That's a day worth repeating. It also illustrates the opportunities automakers see in the performance market, which is expected to grow in the coming years. Ford estimates the segment has expanded 14 percent in Europe and surged 70 percent in North America since 2009. The Detroit Auto Show was evidence of this, and performance cars of every stripe debuted, including the Acura NSX, Ford GT, Alfa Romeo 4C Spider and several others. This isn't a fad. Performance cars aren't going away. The question is why? Stricter CAFE standards are looming in the United States, as are tighter emissions regulations in Europe. And no one expects gas prices to remain low in America. None of this matters for sports cars, and automakers are increasingly using them to elevate their images. That's why Dodge rolled out two 707-horsepower Hellcats last year. It's why Ford has decided to resurrect the GT for road and track. It's why in the depths of bankruptcy, General Motors continued work on the Chevrolet Corvette Stingray, not to mention the Z06. "Great brands are made one car at a time," Ford of Europe president Jim Farley said at the reveal of the Focus RS. Still, companies make those cars for different reasons. View 5 Photos Mainstream brands like Ford and Dodge want to build cars that get people talking, excite their bases and drive more potential customers into the showroom. They probably don't buy a Focus RS or a Hellcat, but suddenly the regular Focus hatch looks a bit hotter, and that V6 Charger seems to be just a touch more muscular. The halo of performance is alive and well in the eyes of automakers and their customers. "It's one of the most effective catalysts for ingenuity and innovation," said Joe Bakaj, vice president of product development for Ford of Europe. That also leads to a trickle-down effect. Some of the technologies inevitably make their way to other products. It's hard to think the new all-wheel-drive system in the Focus RS that distributes torque front to rear and side to side won't be used in other vehicles. It's different for Ferrari and Porsche.

Recharge Wrap-up: Renault-Nissan at COP21, fast charging viability

Nissan and Renault's combined fleet of 200 EVs drove over 175,000 kilometers (about 108,700 miles) during the COP21 environmental summit in Paris. The largest fleet of EVs for any international conference served as shuttles for attendees, saving almost 182 barrels of oil and 18 tons of CO2 emissions. In addition to providing the Nissan Leaf, Nissan e-NV200, and Renault Zoe EV shuttles, the Renault-Nissan Alliance also set up a network of 90 chargers to support the fleet. 13 of the 27 quick and semi-quick chargers will remain in place for public use. Read more in the press release below.Siemens names Ann Arbor, Michigan for its first Center of Excellence for Intelligent Traffic Technology. The company will implement new and upgrade existing traffic technologies in the city, including cloud-based traffic management software, local controller software and an adaptive traffic control system designed to improve traffic flow and safety. In a college town with highly varying numbers of students and visitors throughout the year, "the need to move traffic in and out of the city efficiently is crucial not only for economic and environmental impacts, but for quality of life for Ann Arbor residents," says Marcus Welz, president of Siemens Intelligent Traffic Systems. Many Ann Arborites (your author included) would surely agree. Read more at Green Car Congress, or in the release from Siemens.A study in Ireland found that public fast charging could soon become commercially viable. The researchers found parking spots to be the most popular public charging locations, and that fast chargers saw the most frequent use, suggesting commercial viability for the infrastructure in the short- to medium-term. The study also found that most drivers prefer to charge at home, and do so during peak hours. Incentivization could be necessary to break people from this habit. Read more at Green Car Congress.