2005 Nissan 350z Grand Touring Convertible 2-door 3.5l on 2040-cars

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Nissan 370Z Nismo freshening coming tomorrow

Nissan is set to bring a special to the Fairlady faithful at the annual ZDAYZ fest. Based on the sole teaser and the event it's being unveiled at, it's pretty clear that Nissan is going to be issuing some kind of update to the Nismo version of its 370Z.
What that update is, though, is unclear. We can see a few small visual tweaks, like the horizontal LED running lights and their associated vertical vent. The grille looks reformed as well. Beyond that, though, it looks like we're stuck waiting for the full details until tomorrow afternoon. Until then, take a look below for the world's shortest press release.

2013 Nissan Pathfinder drivers reporting loss of power, 'shuddering' [w/video]

No one appears to have a handle on the numbers, but more than a few owners are registering the same complaint about the CVT-equipped 2013 Nissan Pathfinder: that it "shudders" and loses power when accelerating from a standstill or at low speeds. According to posters at places like Pathfinder Talk, Edmunds, Auto Recalls for Consumers and About Automobile, it happens between about 20 to 40 miles per hour, the sensation is described as being like "driving over a rumble strip" and the power loss occurs for about three to four seconds.
ABC 13 in Houston rode with Pathfinder owner Marlise Holzworth to experience the issue, Holzworth saying that it feels like her vehicle is about to stop when the shudder occurs. Nissan responded to the report, saying that, "A new part has been developed for 2013 Pathfinders that exhibit symptoms similar to those Ms. Holzworth describes. The necessary part should be available at Nissan dealers in June."
Likewise, according to a post on the PathfinderTalk forum, user Krsin97 was informed by a Nissan engineer in April that "[We] are aware of the problem and Nissan is working on update that will come out at the end of June to eliminate the problem."

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.