2014 Nissan Altima S Sedan 4-door 2.5l 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.

2016 Green Truck of the Year, Commercial Green Car of the Year finalists

Not only are commercial-grade haulers getting more green love lately, they're getting more different kinds of green love. The 2016 Green Truck of the Year, the second time the award has been handed out, is being decided by judges from Green Car Journal and the San Antonio Auto & Truck Show. This year the award is joined by the new 2016 Commercial Green Car of the Year, which crowns one of the little vans increasingly used by small business as cargo and delivery vehicles. The Green Truck of the Year finalists are the Chevrolet Colorado Duramax (pictured), Ford F-150, GMC Canyon Duramax, Nissan Titan XD, and Toyota Tacoma. The first three of those were on last year's list, but since they are completely new or upgraded for 2016 - Ford with its all-aluminum body, the General Motors twins with the new diesel Duramax engine - they qualify for entry again. The Ram 1500 EcoDiesel won last year. The Commercial Green Car finalists are the Chevrolet City Express, Ford Transit Connect, Mercedes-Benz Metris, Nissan NV200, and Ram ProMaster City. You can read more details in the presser below, and the awards will be announced in San Antonio sometime during the show from November 19-22. San Antonio Auto & Truck Show Announces 2016 Green Truck of the Year and Commercial Green Car of the Year Finalists SAN ANTONIO, Oct. 22, 2015 /PRNewswire/ -- Green Car Journal and the San Antonio Auto & Truck Show have announced finalists for the 2016 Green Truck of the Year™ and 2016 Commercial Green Car of the Year™ awards. The Green Truck of the Year™ nominees are the Chevrolet Colorado Duramax, Ford F-150, GMC Canyon Duramax, Nissan Titan XD, and Toyota Tacoma. Vying for the all-new 2016 Commercial Green Car of the Year™ award are the Chevrolet City Express, Ford Transit Connect, Mercedes-Benz Metris, Nissan NV200, and Ram ProMaster City. "Over the past few decades, new car models have benefitted from design and technology improvements that have brought higher fuel efficiency and greater levels of environmental compatibility," said Green Car Journal and CarsOfChange.com Editor and Publisher Ron Cogan. "With models like these ten deserving finalists, we're witnessing the pickup and light commercial vehicle field enjoying the same attention." The new Commercial Green Car of the Year™ award is part of an expanded awards program presented at this year's 2015 San Antonio Auto & Truck Show.

Nissan recalls over 120,000 Altimas due to... spare tire inflation?!

A pressure regulator that over- or underinflated spare tires for five days earlier this year has led to a recall of 123,308 units of the 2013 Nissan Altima. Sedans that were manufactured from March 21-26 are those possibly affected by the temporary tire snafu, the recall for which will begin on May 3.
Those notified of the issue can take their sedans to their local Nissan dealer, who will check the tire pressure and correct it if necessary, but we imagine owners can probably just whip out a tire gauge to check and adjust the inflation for themselves. Should you need it, there's an official notice from the National Highway Traffic Safety Administration below with a few more details.