2009 Infinity Fx50 Awd $59k Msrp! Loaded! Navi! Bose! Clean Carfax! Nice! Wow!!! 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.

2019 Infiniti QX50

The 2019 Infiniti QX50 has arrived. All new engine and a whole lot of new technology.

Nissan Pathfinder, Infiniti JX in transmission safety probe

Nissan may be forced to recall 110,000 Pathfinder and Infiniti JX35 crossovers, due to a number of customer complaints. Consumers report suddenly losing power, with repair facilities blaming the issue on faulty transmission cooler line connections. Both the Pathfinder and JX35 use a continuously variable transmission. As of right now, the only vehicles being investigated are from model year 2013.
Nissan has been cooperating with the National Highway Traffic Safety Administration, according to a report from Reuters, and it has developed a fix for the affected vehicles. It's not clear whether this will develop into a full-blown recall, as there have been no known cases of injuries or crashes. But with a potential 110,000 vehicles prone to sudden power loss, a recall seems to be a likely outcome.