2003 Nissan Altima Se Sedan 4-door 3.5l on 2040-cars

Auto blog

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.

Recharge Wrap-up: Fiat 500X emissions, Japan EV sales down

The Fiat 500X exceeds EU emissions limits, according to environmental lobby group DUH. In dyno tests, DUH found NOx emissions in the diesel-powered 500X to be 11 to 20 times the limit with a warm engine, but closer to the limit with a cold engine. Testing of vehicles from Fiat and other automakers "point towards defeat devices," says DUH campaigner Axel Friedrich. Fiat Chrysler Automobiles (FCA) offered no comment in response to the accusations. Read more from Reuters. A UK study finds that about 20 percent of the benefits from fuel efficient vehicles are negated by a tendency for people to drive them more. The study, which covers the years 1970 to 2011, finds a significant "rebound effect," when consumers use more of a cheaper energy source. It suggests these drivers drive more not because of the fuel efficiency, but because of the lower operating costs. "Until now, we didn't know the size of this effect for British motoring," says Dr. Lee Stapleton, Research Fellow for the University of Sussex Centre on Innovation and Energy Demand. "We found evidence of a significant, long-term rebound and expect our results to be of interest for public policy." Read more at Green Car Congress. Japanese EV sales have declined for the first time ever. Sales of electric vehicles slid 22 percent in 2015, leaving them at the same levels as 2012. Low gasoline prices are to blame, as well as the late arrival of the updated Nissan Leaf, which caused potential customers to hold off on their purchase. This allowed the Mitsubishi Outlander PHEV to take the lead as Japan's best selling EV. The Toyota Prius Plug-In came in third place in EV sales, with the BMW i3 close on its heels. Read more from EV Sales. Featured Gallery 2016 Fiat 500X: First Drive View 34 Photos Related Gallery Mitsubishi Outlander PHEV Concept-S: Paris 2014 View 12 Photos News Source: Reuters, Green Car Congress, EV SalesImage Credit: Copyright 2016 Drew Phillips / AOL Green Fiat Mitsubishi Nissan Emissions Fuel Efficiency Electric recharge wrapup

Nissan wants an American driver for its Le Mans team

"We'll use every driver development tool we have to take them to the next level, but they will also have to step up." - Darren Cox
Nissan is aiming to put an American behind the wheel of one of its LMP1 racecars in 2016 as part of plans to grow its motorsports program in the United States.