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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.

Pontiac Aztek enjoys rebirth thanks to Millennials

Apparently, Millennials – those between 18 and 34 – aren't afraid to look different on the road, and they like performance, too. A new study by Edmunds is discovering some surprising vehicle choices by this group. Among them, the long-derided Pontiac Aztek is getting a new day in the sun with 25.5 percent its buyers coming from this generation in the first half of 2015. For comparison, Millennials represent an average of 16.8 percent of used car purchases. The Aztek is slowly shaking its reputation as a styling abomination, which seems tied to its appearance on Breaking Bad. The show premiered in 2008, and the Pontiac has been on this list for four of the past five years, according to Edmunds. It even led the pack in 2010. A recent Retro Review from MotorWeek also showed that the crossover wasn't always so hated. While it's still a shock to see the Aztek on any popularity list, the awkward-looking crossover only ranks sixth among Millennials. The vehicle with the biggest portion of buyers from the generation is the Dodge Magnum with 27.6 percent. According to Edmunds, the bluntly styled wagon is especially popular in Detroit and Chicago. The Chrysler Pacifica comes in a close second at 27.3 percent. When it comes to used cars, value and utility appear to trump just about anything else for many Millennial buyers," Edmunds analyst Jeremy Acevedo said in the report. Young buyers aren't afraid of sporty rides, either. The Subaru WRX has 26.4 percent Millennial buyers to rank third place on the list, and the Volkswagen R32 takes fifth at 25.7 percent. Just a few points lower in seventh place is the Nissan GT-R at 25.4 percent, and the final performance machine in 10th place is the Lexus IS-F with 24.7 percent. Related Video:

2015 Nissan Murano to hit the stage in NY

When the Nissan Murano launched in the early-2000s it was one of the first crossovers to eschew truck-like looks in favor of more sporty styling. For the third generation, Nissan is rumored to be taking the CUV's design even farther with inspiration from the wild Resonance concept that debuted at the 2013 Detroit Auto Show. According to Edmunds, Nissan will unveil the next-generation, 2015 Murano and an unnamed concept at the New York Auto Show in April.
The new Murano will go on sale this fall on the same front-wheel drive platform as the Altima, Pathfinder and next-gen Maxima. Its size will be roughly unchanged compared to the current model, and there won't be a seven-seater option. Nissan spokesman Dan Bedore told Edmunds that it already offers "three rows in the Rogue as an option and three rows in the Pathfinder for everything. We don't need another three-row crossover." There will also be a rumored hybrid version using the Pathfinder's supercharged 2.5-liter four-cylinder engine, a 22-horsepower electric motor and lithium-ion battery. To disappoint the dozen people who will miss it, the much-maligned Murano CrossCabriolet will not make it to the third generation. Let's all shed a tear.