2005 Nissan Sentra S Sedan 4-door 1.8l 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.

How and why Nissan nearly killed off Infiniti

Launched in 1990, Infiniti was expected to be Japan's answer to BMW (Lexus would end up chasing Mercedes-Benz). Yet things went awry almost right out of the gate. Overlooking the fledgling automaker's now infamous early marketing campaign, its product line over the past twenty-four years has been a roller coaster ride of strong hits (Q45, FX35 and G35) and frustrating misses (M30, I30 and QX4).
In a recent interview with Ward's Auto at the Detroit Auto Show, Nissan Executive Vice President Andy Palmer revealed that the company's luxury brand was almost cancelled by CEO Carlos Ghosn as unnecessary. Infiniti, like most premium marques owned by a volume manufacturer, had fallen into the trap of losing autonomy and pushing its high-end product just like its mainstream models.
The one obvious exception to this industry blunder, said Palmer, was VW Group's Audi brand. Realizing that Audi's impressive comeback over the past two decades shamed even that of actor Robert Downey Jr., Nissan hired Audi veteran Johan de Nysschen to bring Infiniti to its intended glory - and protect it from extinction. Check out the complete interview here.

Nissan adds 2013 Titan to gearshift recall

Nissan has added the 2013 Titan to the list of vehicles recalled over potential gearshift issues. Just a few days ago, the automaker recalled nearly 20,000 NV Vans for a problem with the shift lever assembly that could cause the gear selector to read inaccurately. Now Nissan is recalling certain 2013 Titan pickup trucks manufactured between December 17, 2012 and February 20, 2013 and equipped with column-mounted shift levers, though for a different fault. The pickups were built using certain chemicals that could cause the brake-shift interlock mechanism to fail over time. If that happens, the truck could be shifted out of Park without the driver's foot on the brake.
As a result, the truck could roll away and cause an accident or injury. Nissan says it will remedy the fault free of charge. Owners can expect to be notified once the campaign begins on or around April 8. You can read the full National Highway Traffic Safety Administration notice below for more information.