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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.

Total auto recalls already on record pace in 2014

If you've noticed that there have been more recalls than usual this year, you may be on to something. According to a report from the National Highway Traffic Safety Administration, the US market is on pace to break a record for recalls. In 2013, 22 million cars were recalled. We're only a third of the way through 2014, though, and we've already halved that figure, with 11 million units recalled. That's wild.
Considering the past few months, it shouldn't be a surprise that General Motors is leading the charge, with six million of the 11 million units recalled coming from one of the General's four brands. Between truck recalls, CUV recalls and the ignition switch recall, 2014 hasn't been a great year for GM.
Other recall leaders include Nissan (one million Sentra and Altima sedans), Honda (900,000 Odyssey minivans), Toyota (over one million units in a few recalls), Volkswagen (150,000 Passat sedans), Chrysler (644,000 Dodge Durango and Jeep Grand Cherokee SUVs) and most recently, Ford (434,000 units, the bulk of which were early Ford Escape CUVs). So while it's been a bad year for GM so far, its competitors aren't doing too well, either.

2014 Nissan Pathfinder Hybrid arrives with supercharged engine, 26 mpg combined

Nissan just launched the fully redesigned Pathfinder for the 2013 model year, and now, there's a fuel-sipping hybrid version making its debut here at the New York Auto Show. The 2014 Pathfinder Hybrid packs all of the same features found in the standard crossover, but offers slightly better fuel economy and an improved cruising range, to boot.
The new hybrid is powered by a 2.5-liter supercharged engine (we're assuming it's a four-cylinder, though Nissan hasn't specified) coupled with a lithium-ion battery and 15-kilowatt electric motor, capable of producing 250 horsepower and 243 pound-feet of torque - 10 less horsepower but three more pound-feet than the standard V6 Pathfinder. Nissan says the hybrid crossover will be rated at 25/27 miles per gallon (city/highway), with a 26-mpg combined rating. This means that on a full tank, the cruising range of the Pathfinder Hybrid is a cool 526 miles.
What's cool about the hybrid packaging is that Nissan has managed not to have it interfere with any of the interior functionality - the Pathfinder Hybrid still packs just as much cargo and passenger space as its naturally aspirated sibling. Official pricing has not been announced, but Nissan expects the hybrid to command an additional $3,000 over the standard model.