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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.

Autoblog Podcast #380

Episode #380 of the Autoblog podcast is here, and this week, Dan Roth, Chris Paukert and Seyth Miersma talk about the Fiat-Chrysler five-year plan, the seeming demise of the Nissan Cube, and proposed legislation to require speed limiters with a 68-mph maximum on America's tractor trailers. We start with what's in the garage and finish up with some of your questions, and for those of you who hung with us live on our UStream channel, thanks for taking the time. Check out the new rundown below with times for topics, and you can follow along down below with our Q&A. Thanks for listening! Autoblog Podcast #380: Topics: Fiat-Chrysler five-year plan Nissan Cube on the way out? Big rig speed limiters coming? In the Autoblog Garage: 2015 Mercedes-Benz S63 AMG 2014 Chevrolet Sonic RS Sedan 2014 Honda Odyssey Touring Elite Hosts: Dan Roth, Chris Paukert, Seyth Miersma Runtime: 01:44:17 Rundown: Intro and Garage - 00:00 Fiat Chrysler Plan - 29:40 Nissan Cube - 01:07:33 Semi Speed Limiters - 01:17:33 Q&A - 01:27:35 Get the podcast: [UStream] Listen live on Mondays at 10 PM Eastern at UStream [iTunes] Subscribe to the Autoblog Podcast in iTunes [RSS] Add the Autoblog Podcast feed to your RSS aggregator [MP3] Download the MP3 directly Feedback: Email: Podcast at Autoblog dot com Review the show in iTunes Auto News Earnings/Financials Plants/Manufacturing Podcasts Rumormill Chevrolet Chrysler Dodge Fiat Jeep Nissan nissan cube speed limiters

Nissan Titan Wounded Warrior project lands in time for Veteran's Day

We last featured the crowdsourced Project Titan pickup back in September, back when Nissan revealed that its big, bruising custom pickup would take to the wilds of Alaska with a pair of veterans from the Wounded Warrior Project at the wheel.
Now, their journey across the wilds has been fully revealed as part of a 22-minute short film. David Guzman and Kevin McMahon are the pilots of the brutish truck, and while the film is ostensibly focused on the journey and the challenges that come with it, the release of the video on Veterans Day (Remembrance Day or Armistice Day, depending on where you're from), gives some indication to the dominant theme of the story - recovery.
The two travel across Alaska in the Titan on different missions, working with both veterans and civilians afflicted with post-traumatic stress disorder, as well as supporters of the Wounded Warrior Project. From the avalanche-surviving photographer who's suffering from PTSD to an Air Force veteran who routinely takes recovering vets on fishing trips, the pair experience the many efforts at recovery and support throughout the course of the missions and their journey.