2009 Nissan Maxima Sv Sedan 4-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.

CES 2020 and Carlos Ghosn | Autoblog Podcast #609

Welcome to a new decade of the Autoblog Podcast. In this week's episode, Editor-in-Chief Greg Migliore is joined by Senior Editor Alex Kierstein and Senior Editor, Green, John Beltz Snyder. First they talk about their early impressions of CES 2020 in Las Vegas, in particular how interesting Sony's Vision-S Concept is. Then they talk about the intriguing saga and daring escape of former Nissan boss and global fugitive Carlos Ghosn. After that, they turn their attention to what they've been driving, including the Genesis G70, Chevy Blazer and Hyundai Santa Fe. Finally, they help a listener pick a new fun toy to replace an unloved Porsche Cayman in the "Spend My Money" segment. Autoblog Podcast #609 Get The Podcast iTunes – Subscribe to the Autoblog Podcast in iTunes RSS – Add the Autoblog Podcast feed to your RSS aggregator MP3 – Download the MP3 directly Rundown CES 2020 And that excellent Sony Vision-S Concept What's going on with Carlos Ghosn? Cars we're driving:2020 Genesis G70 2.0T Sport RWD 2020 Chevrolet Blazer Premier AWD 2020 Hyundai Santa Fe 2.0T AWD Spend My Money Feedback Email – Podcast@Autoblog.com Review the show on iTunes Related Video:

NHTSA urges owners of recalled Takata airbag vehicles to take immediate action

The National Highway Traffic Safety Administration and the Department of Transportation are taking the unusual step of issuing a followup press release urging owners of certain recalled vehicles "to act immediately" to fix their cars and trucks. The problem in question concerns the repair campaigns for rupturing Takata airbag inflators issued in June and covers a long list of models from Toyota, Lexus, Honda, Acura, Mazda, BMW, Nissan, Infiniti, Buick, Cadillac, Chevrolet, GMC, Oldsmobile and Pontiac.
While NHSTA doesn't specifically say why the recall is vital in the new release, Toyota's own explanation in its newly announced renotification campaign earlier today sheds some new light on the topic. According to the Japanese automaker, in testing, Takata found a possible link between the rupturing airbag inflators and high humidity. NHTSA is advocating that all owners pursue repairs immediately if they haven't already done so already. This is especially crucial for those drivers especially in Florida, Puerto Rico, Guam, Saipan, American Samoa, Virgin Islands and Hawaii because of the humid conditions there.
We don't need to tell you how dangerous an inadvertent airbag deployment could be - even in a stationary vehicle - but adding to the Takata issue is fears that the deployment could lead to shrapnel being sprayed into the cabin.