2014 Nissan Altima 2.5 S 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.

Chevy Volt 'acceptable,' Nissan Leaf 'poor' in new IIHS safety tests

Ford C-Max Hybrid also scored "acceptable" rating. With US Nissan Leaf sales up almost 30 percent during the first half of the year, the only thing that might be able to stop the battery-electric vehicle is a good, stiff barrier. Unfortunately, thing's aren't always pretty when that happens in the real world, according to new tests from the Insurance Institute for Highway Safety (IIHS). Things with the Chevrolet Volt extended-range plug-in are a little bit rosier, though. The two plug-in vehicles were part of a batch of a dozen vehicles that just went through the IIHS's "small overlap" test, in which the driver's side front corner of the vehicle is crashed into a rigid barrier at 40 miles per hour. Out of the dozen, only the Mini Cooper Countryman was given a "good" rating. Five vehicles, including the Volt and the Ford C-Max Hybrid, were rated "acceptable," two were "marginal" and two, including the Leaf, were "poor." Plug-in vehicles are unique in the crash-test context because of their relatively large battery sizes. In the Volt's case, the driver had a "low risk" of injury, said the IIHS. But the Leaf's crash substantially pushed back the instrument panel and steering column, creating a scenario where the driver was "likely" to sustain leg injuries. The batteries in both the Leaf and the Volt passed safety tests specifically targeted at things like thermo and electrical properties and overall integrity. "Nissan is proud of the Leaf's 'Good' rating in all other IIHS tests, a 4-star NCAP rating from NHTSA and its IIHS Top Safety Pick rating in all previous years since the car's release," the company said in an e-mail sent to AutoblogGreen. "As for the performance of the 2014 Leaf in the 'small overlap frontal test,' Nissan will continue to review these and other results from the IIHS 'small overlap frontal test' as we seek opportunities for improvement." Check out the IIHS's press release and small car crash-test video footage below. Range of ratings: Small car ratings run the gamut in challenging small overlap front test The Mini Cooper Countryman is the only small car to earn a good rating among the latest group of 12 cars subjected to the Institute's small overlap front crash test. Two electric models and a hybrid also are in the mix, with varied results. The electric-powered Chevrolet Volt (with a gasoline engine "range extender") earns an acceptable rating, while its battery-electric rival, the Nissan Leaf, earns a poor rating.

2015 Nissan GT-R Nismo is Japanese for "Zero Competition"

It was only a little more than a year ago that we were wondering if there would be a new Nissan GT-R, now here we are writing about the introduction of two of them. Carlos Ghosn himself unveiled the new 2015 Nissan GT-R Nismo and the standard-in-name-only 2015 GT-R on which it is based. The Nismo is all about ape-chested mojo, coming with the tagline "Zero Competition," GT3-derived tweaks without and within and a 'Ring time of 7:08.679.
Nissan also brought the actual 'Ring-running car to the event and you'll notice that it has a different rear wing than the two show cars. We were told that the wing on the time-setting car would be available on the car that goes on sale, Nissan intending to keep its "production car" promise.
You can check out the Nismo above in the new Dark Matte Grey exterior hue and in Brilliant White Pearl, as well as the new GT-R, its new Ivory interior and LED light signature below. We haven't written this in a while, so allow us to bring the challenge back: Porsche - your move...