2008 Nissan Sentra Se-r Spec V Clean Car Low Miles 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.

Renault and Nissan forge deeper alliance

If the automotive industry's current era could be summarized by one trend - from a corporate aspect, anyway - surely it would be conglomeration. But of all the major auto groups that have emerged over the past several years, none have kept themselves at arm's length quite like the Renault-Nissan Alliance.
Much like Fiat and Chrysler, Renault and Nissan are presided over by a common chief executive. But whereas Sergio Marchionne's Italian-American alliance has moved swiftly from a transatlantic partnership to a merged company in the span of less than five years, Carlos Ghosn's Franco-Japanese alliance has stood oceans apart since 1999. But now the Renault-Nissan Alliance is following the lead set by Fiat Chrysler Automobiles in bridging that distance through several key measures.
For one, Renault and Nissan will make increased use of common platforms, R&D, systems and testing. The two automakers will also cooperate more closely on manufacturing and supply chain management, purchasing and human resources. To manage the increased cooperation, the alliance has appointed several new executive vice presidents from within its ow ranks and a new management committee to be chaired by Ghosn, details about which you can read in the press release below.

The art of racing the Nissan GT-R

There's no question that the Nissan GT-R is one of the very fastest cars that money can buy, and that its sophisticated all-wheel-drive system and active suspension give its drivers an absurd level of control at speed. In fact, the GT-R's technical brilliance and video-game quickness often spur armchair critics to make absurd claims that kind of amount to: "The car basically drives itself."
Having a bit of fun with those particularly salty members of the peanut gallery, YouTube producers at That Racing Channel have put together an instructional video about the finer points of GT-R driving and street racing. Scroll down below to get an idea about just how difficult Godzilla can be to keep hold of at the limit.