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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.

Recharge Wrap-up: Nissan Leaf top environmental performer, 50,000th Renault Zoe

Renault has produced its 50,000th Zoe electric car. A Frenchwoman named Sylvie took ownership of the milestone vehicle at the Flins plant where it rolled of the line. She says her children helped convince her to buy the all-electric vehicle, which Sylvie intends to use as a daily driver. The Renault Zoe is Europe's best selling EV since its launch in 2013. Renault reports a 98-percent satisfaction rate with the Zoe. Read more in the press release from Renault. Toyota will use a biosynthetic rubber called biohydrin in its engine and drive system hoses beginning in May 2016. Jointly developed by Toyota, biohydrin is a plant-based rubber with a 20-percent reduction in material lifecycle carbon emissions compared to petroleum-based rubber. Toyota plans to use the compound in even more components in the future, including brake and fuel line hoses. Read more from Toyota. So far in 2016, only 27.5 percent of hybrids and EVs are traded in for another electrified vehicle, according to Edmunds. That's down from 38.5 percent in 2015. 33.8 percent of electrified vehicles are traded in for SUVs. Despite the trend of EV and hybrid owners switching back to traditionally powered vehicles, average fuel economy isn't suffering. "This is an economics trend, since today's low cost of gas no longer makes it worth paying the price premium of hybrids and EVs," says Edmunds Director of Industry Analysis Jessica Caldwell. "And there are so many fuel-efficient vehicles on the market today that environmental concerns weigh less than they might have in years past. When you're buying a vehicle that can get over 30 mpg, you can still say you're doing your part to help the environment." Read more from Edmunds. Environmentally, electrified vehicles outperform their conventional combustion counterparts throughout their lifecycle. A study from the Automotive Science Group (ASG) finds that while production of advanced powertrains comes with a greater financial burden, most vehicles make up for it through efficiencies during their use phase. The ASG lists the 2016 Nissan Leaf as its best performer, with 47 percent fewer greenhouse gas emissions than the best-performing conventionally powered car, the Honda Fit. Rounding out the ASG's top five environmental performers are the Ford Focus Electric, Chevrolet Volt, Toyota Prius Two Eco, and Hyundai Sonata Plug-In Hybrid.

Autoblog Podcast #393

Episode #393 of the Autoblog Podcast is here, and this week, Dan Roth, Steven Ewing, and Michael Harley talk about Monterey Car Week, the Woodward Dream Cruise and Dodge Charger Hellcat, and the latest round of mid-engine Corvette rumors. Dan also had the chance to speak with Jeffrey Rothfeder, author of Driving Honda, a new book that takes a look inside the automaker. 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 #393: Topics: Monterey Car Week Jeffrey Rothfeder (Driving Honda) interview Woodward Dream Cruise + Dodge Charger Hellcat Mid-Engine Corvette rumors just won't die In The Autoblog Garage: 2014 Jaguar F-Type V6 S Convertible 2015 Chevrolet Silverado 2500HD 4X4 CNG 2014 Nissan NV200 SV Hosts: Dan Roth, Steven Ewing, Michael Harley Runtime: 02:10:41 Rundown: Intro and Garage - 00:00 Monterey Car Week - 37:08 Jeffrey Rothfeder - 52:17 Woodward 2014 - 01:28:11 Mid-Engine Corvette - 01:44:30 Q&A - 01:56:53 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 Podcasts Rumormill Chevrolet Dodge Jaguar Nissan Pebble Beach mid-engine corvette dodge charger hellcat