2007 Nissan 350z Convertible 2-door 3.5l on 2040-cars

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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.

2013 Nissan Pathfinder: April 2013

Not Just For Families
Since our long-term 2013 Nissan Pathfinder joined the Autoblog Garage in late December of last year, the only time I've really spent with it has been during the short periods of time between my co-workers' longer loans. Until now, my experiences with our Mocha Stone tester have been limited to pick-ups and drop-offs at various locations around the greater Michigan/Ohio area, not to mention keeping the vehicle clean inside and out, as well as handling our first bit of scheduled maintenance in late March.
I was pleased, then, to actually be able to spend most of the month of April with our Pathfinder, finally giving me a chance to see what everyone else does and does not like about Nissan's new crossover. But here's the thing: I'm admittedly not the ideal person to test a family-minded vehicle. I'm single and in my late twenties, so something like our other long-term car, the 2013 Hyundai Veloster Turbo, is better suited to meet my everyday needs.

Nissan pokes fun at Tesla's New Jersey woes, then deletes Tweet

Ever have one of those moments when you release something out onto Twitter, only to think better of it a little while later and reach for that garbage can icon? If so, you are not alone. In fact, you're in the company of a certain Japanese automaker, who recently joined the ranks of those who've suffered an embarrassing bout of tweetus deletus. The Nissan Leaf social media team apparently thought it would be amusing to take a light poke at Tesla Motors and its New Jersey dealer fight woes on its Twitter feed and put together the cheeky graphic which you see above. It was originally published on the micro-blogging network accompanied by the text, "It's okay #NewJersey, you can still #GoElectric with the #NissanLEAF #EV." Funny, right? Not to everyone. The image attracted a bit of mild criticism which, to their credit, Nissan responded to saying, "It's all in #EV love." Soon, however, the original image disappeared from the @NissanLEAF feed. Luckily, we saved a copy for your edification. Rob Robinson, senior specialist of social communications for Nissan, told AutoblogGreen that the Leaf Twitter account is run by an agency, and that the tweet in question, "Was not a tweet that was reviewed or approved by Nissan. We saw it and asked them to take it down." As for the reasoning, Robinson said that, "We thought it was a discussion we didn't need to be weighing in on." While we can see the Nissan point of view, we also appreciate the attempt at being irreverent. Anything to break up the monotony of the stale toast the account usually offers up – "What would you nickname your Nissan Leaf if it was Ocean Blue?" which is the last undeleted Tweet available on the feed, as of this writing. We actually applaud the intention of the Tesla post. It all makes us wonder, though, if the social media team over there isn't in need of a little input on how they might improve its outreach. Since we know our readers are not shy in offering suggestions, we ask you to leave your thoughts and ideas for them in the Comments.