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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.

2015 Nissan Murano to hit the stage in NY

When the Nissan Murano launched in the early-2000s it was one of the first crossovers to eschew truck-like looks in favor of more sporty styling. For the third generation, Nissan is rumored to be taking the CUV's design even farther with inspiration from the wild Resonance concept that debuted at the 2013 Detroit Auto Show. According to Edmunds, Nissan will unveil the next-generation, 2015 Murano and an unnamed concept at the New York Auto Show in April.
The new Murano will go on sale this fall on the same front-wheel drive platform as the Altima, Pathfinder and next-gen Maxima. Its size will be roughly unchanged compared to the current model, and there won't be a seven-seater option. Nissan spokesman Dan Bedore told Edmunds that it already offers "three rows in the Rogue as an option and three rows in the Pathfinder for everything. We don't need another three-row crossover." There will also be a rumored hybrid version using the Pathfinder's supercharged 2.5-liter four-cylinder engine, a 22-horsepower electric motor and lithium-ion battery. To disappoint the dozen people who will miss it, the much-maligned Murano CrossCabriolet will not make it to the third generation. Let's all shed a tear.

NA auto output to reach 11-year peak

According to Automotive News, automakers are expected to manufacture 16 million light vehicles in North America in 2013. That's up 500,000 units from last year and marks the largest number since 2002. The prediction comes courtesy of LMC Automotive and IHS Automotive, which point to the improving US economy as a bellwether for total production. LMC Automotive says North America will produce 16 million vehicles while IHS has a slightly more optimistic forecast of 16.1 million units. A total of seven automakers are slated to increase production on the continent this year. Nissan is set to see the largest jump at 20 percent over last year.
Volkswagen, meanwhile, is one of the only manufacturers predicted to scale back production. Analysts expect the German company's output to fall by 23 percent to 170,000 units, thanks in part to slow demand for the Volkswagen Passat and Jetta.