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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.

As of today, Nissan has sold 50,000 Leafs in the US, 115,000 globally

Watch out, America, there are 50,000 Nissan Leaf electric vehicles prowling your streets. That's the official word from Nissan, which says it has just delivered the 50,000th Leaf – a black SL model – to Todd and Lisa Bolt in Dallas, Texas. Todd is a pastor at the Gateway Church in Southlake, where there almost two dozen Leaf drivers who call themselves the "Blessed LEAFs Club." We're not making that up. Divinely inspired or not, Todd said in a statement that the EV completely meets the family's needs and that, "I don't know why we'd buy another gas car." Last September, Nissan announced it had sold 35,000 Leaf EVs in the US so far, and the 25,000 mark came in May last year. Globally, "nearly 115,000" Leafs have been sold, which makes Nissan's workhorse the most popular EV by a long shot. To celebrate the occasion, Nissan has put together an infographic (click to enlarge) showing the cumulative effects of all those electric vehicles on the roads. While they're only estimates based on taking the actual data from the CarWings connected vehicles (which make up 55 percent of the total fleet) and extrapolating, the numbers are still impressive. Around 906,000,000 miles driven, which means 241,000 metric tons of CO2 saved from going into the air. 50,000 Leaf sales is a big deal, sure, but we're much more keen on those cleaner air figures. Read more below. This content is hosted by a third party. To view it, please update your privacy preferences. Manage Settings. NISSAN DELIVERS 50,000TH ALL-ELECTRIC LEAF IN U.S. TO TEXAS FAMILY DALLAS (May 23, 2014) -- Nissan, the global leader in electric vehicle (EV) sales, achieved another milestone this month as Dallas residents Todd and Lisa Bolt made Nissan LEAF the first all-electric model to hit 50,000 sales in the U.S. The Bolt family took delivery of their black LEAF SL earlier this month at AutoNation Nissan of Lewisville. Thanks to enthusiastic owner advocates, robust public charging infrastructure and the launch of a successful free charging promotion, Dallas – and the state of Texas – have become hot growth markets for LEAF. So far in 2014, LEAF sales in the Dallas-Fort Worth metroplex have grown by about 50 percent over the previous year, with that growth set to accelerate faster thanks in part to the introduction of a new state tax rebate of up to $2,500 on the purchase or lease of a new Nissan LEAF.

Renault's push for more affordable EVs has global implications

The Renault K-ZE is a small electric car that signals a big change in how the French automaker plans on bringing electric vehicles to the masses. Set to go on sale in China beginning in 2019, the K-ZE is meant to have the design of a sport-utility vehicle, but it's on a supermini-sized frame. While it's set to arrive in Europe by 2021, this petite EV could eventually impact electric sales here in the U.S., too. That's because Nissan, maker of the Leaf EV, is part of the Renault-Nissan-Mitsubishi Alliance, a three-pronged automaker with a huge global presence. In China, however, the Renault brand has been absent from the country's booming market for electric vehicles — driven in large part by government mandates to combat air pollution by promoting cleaner, zero-emission cars and trucks in cities. Speaking ahead of the K-ZE's debut this week at the 2018 Paris Motor Show, Carlos Ghosn, the chairman and CEO of Group Renault, stated the company "was a pioneer and is the European leader in electric vehicles." To this, he added the K-ZE is meant to have global reach and bring costs down for the consumer. "We are introducing Renault K-ZE, an affordable, urban, SUV-inspired electric model combining the best of Groupe Renault: our leadership in EV, our expertise in affordable vehicles and in forging strong partnerships," said Ghosn. In China, the K-ZE will be manufactured as part of a joint partnership in cooperation with Renault, Nissan and the Chinese automobile firm Dongfeng Motor Group. The range of the K-ZE is expected to be about 150 miles per charge, or roughly the current range in the 2018 Leaf EV. Except the K-ZE is almost three feet shorter than the Leaf, which means Renault is getting a lot more range from a smaller and lighter amount of batteries. While a car this size would be too small for the U.S. market, the technology beneath this teeny hatchback/SUV is certain to make an appearance here in the years ahead. At the 2018 Geneva Motor Show, Nissan provided a hint of its future European EV plans, courtesy of the IMx Kuro Concept. This edgy-looking electric crossover is a good indication as to the design direction of Nissan's next range of electric crossovers and SUVs over the next 3-5 years — look for the design and tech to similarly migrate stateside.