2003 Nissan Xterra Se Sport Utility 4-door 3.3l 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.

Honda, Nissan and Mazda recalling 3 million vehicles for airbag inflators

Three million more vehicles can be added to the worldwide tally to be repaired for the faulty airbag inflators supplied by Takata. Honda, Nissan, and Mazda have all issued recalls to replace the bad part, including about 1.2 million of them in North America. NHTSA has been investigating all three companies, plus Chrysler and Toyota, for potentially affected vehicles.
Honda is recalling roughly 1.02 million Civic, CR-V, Odyssey and Element models In North America, built between April 2000 and October 2002. Mazda needs to repair 14,794 units of the RX-8 and Mazda6, and Nissan has 228,000 vehicles in North America to be fixed.
Chrysler is also starting what it calls a "regional field action" to replace the inflators in the 2006 Dodge Charger, according to a company spokesperson. The company says that it has not yet found the problem in any of its vehicles, but it's being done "out of an abundance of caution." The final number of Chargers affected will be announced later this week.

New Nissan Nismo model coming to Chicago

Nismo has been steadily growing from a niche label for JDM aficionados to a bona fide performance sub-brand for Nissan. And it will grow by one more model next week when the doors open at the Chicago Auto Show. Nissan hasn't revealed exactly what it has in store just yet, but whatever it is, it'll be an all-new model we haven't seen before. The Datsun performance studio has already given us amped-up versions of the Juke, 370Z and GT-R, offers several more versions in markets overseas and has displayed concept versions of other Nissan models as well. We're hoping that whatever Nismo has lined up for Chicago will be ready for production and available Stateside, but we'll have to wait a little while longer to say for sure.