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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

Watch some vintage F1 cars blast up a Japanese mountain road

It's a rare treat to see classic Formula One cars racing anywhere, but watching them on a Japanese mountain road is absolutely sublime. The folks behind Motorhead from Japan took over the toll road's twisting stretch of tarmac to turn this impossible dream into a reality. The unusual opportunity of a closed mountain road would be a waste for only two vehicles, and there were plenty of drivers in amazing machines that wanted to blast up the hill. After the vintage F1 cars got their turn, some drifters in a Nissan GT-R and a Toyota GT86 added some tire smoke to the misty mountain air. A couple more GT-R racecars and some modern sports cars eventually joined them. Before the rain hit, this team had quite a party going on. This video features amazing camera work, but the music unfortunately drowns out the chance to hear these amazing racecars. If watching this leaves you wanting more, Motorhead released a video last year of another group of impressive performance vehicles on the mountain road.