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Autoblog Podcast #416

Episode #416 of the Autoblog Podcast is here, and this week, Dan Roth, Steven Ewing, and Brandon Turkus talk about the 2016 Mazda MX-5 Miata, seeing the 2016 Nissan Maxima in the company's Super Bowl ad, and GMC's potential plans for a Jeep Wrangler fighter. Of course, the podcast starts with what's in the garage and finishes 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 rundown with times for topics, and you can follow along down below with our Q&A. Thanks for listening! Autoblog Podcast #416 Topics 2016 Mazda MX-5 Miata first drive 2016 Nissan Maxima previewed in Super Bowl ad GMC mulling Jeep Wrangler fighter In The Autoblog Garage 2015 Hyundai Genesis 5.0L V8 2015 Honda CR-V Long-Term 2015 Volkswagen GTI Hosts: Dan Roth, Steven Ewing, Brandon Turkus Runtime: 01:36:43 Rundown Intro and Garage - 00:00 Maxima – 30:48 Miata – 41:46 GMC/Wrangler – 59:14 Q&A - 01:11:13 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 GMC Honda Hyundai Jeep Mazda Nissan Volkswagen vw gti nissan maxima

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.

Some NY cabs could avoid hybrid ban

The Nissan NV200 is having a rough go of it as New York City's Taxi of Tomorrow. The Greater New York Taxi Association wants the van banned on the grounds that it isn't a hybrid, and has gone so far as to sue the city to keep the NV200 out of taxi fleets. According to The New York Times, the city has responded by proposing to allow taxi drivers to use certain hybrid vehicles. The Taxi and Limousine Commission's proposal would allow any vehicle with an interior volume of 138 cubic feet or more. Unfortunately, that excludes nearly every machine that isn't the size of the NV200.
Technically, Nissan is working on a hybrid version of the Taxi of Tomorrow, but it may be years before that model hits the streets, and the Greater New York Taxi Association isn't satisfied with the city's offer. In a statement, the Association said, "These rules look like they have been created to short-circuit the litigation. We do not consider this to be a serious proposal."