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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.

Chinese-designed Nissan Lannia Concept debuts in Beijing

Nissan showed off a stylish new concept car to the assembled crowds of media at the Beijing Motor Show. The Lannia Concept is... well, it's not that easy to describe. It's kind of a sedan, only it looks a bit like a fastback from the rear. But for a twist, it has an ever-so-small rear deck. Regardless of how we'd classify it, it's a seriously sharp piece of styling, thanks to its unique shape and flowing character lines.
If the Lannia's styling appears familiar, it's because we've sort of seen it before. There's more than a little bit of inspiration from the Friend-Me Concept. The Lannia's overall shape is similar to the Friend-Me, while both the front and rear clips look decidedly more production ready. Considering this evolution, we shouldn't rule out a production Lannia in the next few years. And if Nissan's product boss, Andy Palmer is any indication, the new model might not be limited to China.
"It was designed by Chinese, built by Chinese for the Chinese people, and ultimately, for the world," Palmer said in a statement. If Nissan can keep this sharp styling, this could prove a compelling buy in a number of markets.

Autoblog Podcast #318

Toyota back on top, Barrett Jackson, Crowdsourcing your Dodge Dart payments, Nissan and Toyota double down on pickups
Episode #318 of the Autoblog Podcast is here, and this week, Dan Roth, Zach Bowman and Michael Harley talk about Toyota regaining the No. 1 sales crown, getting your friends and family to buy you a Dodge Dart, Barrett-Jackson, and Toyota and Nissan remaining committed to their pickup trucs. We wrap with your questions, and for those of you who hung with us live on our UStream channel, thanks for taking the time. Keep reading for our Q&A module for you to scroll through and follow along, too. Thanks for listening!
Autoblog Podcast #318: