2012 Nissan Sentra 2.0 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.

Nissan reveals NP300 Navara pickup, is it the next Frontier? [w/videos] [UPDATE]

UPDATE: Statement from Nissan added, below.
After plenty of teasing, Nissan has finally revealed the NP300 Navara pickup, previewing America's next Frontier. Now, before we dive into all the info on this new midsize pickup, it's important to note that we don't quite have the official details on the American-spec truck, so there's quite a bit of information here that might not carry through to the North American market.
Depending on the market, the Navara will offer either a four-cylinder diesel or a four-cylinder gas engine, both of which displace 2.5 liters. Nissan claims both engines have been improved, with the oil-burner producing 188 horsepower and 332 pound-feet of torque. There aren't specific figures on the gas engine, although we should expect that it will see a nice bump from the current Frontier's four-cylinder, which offers up 152 hp and 171 lb-ft of torque. It's not clear if a V6 will be available in the US, as there's no mention of it in the Navara's literature.

North Carolina now charging $100-per-year EV road-use fee

Tobacco Road just got a little more expensive for drivers of electric vehicles such as the Nissan Leaf and Tesla Model S. This year, North Carolina started instituting an annual $100 road-use fee for electric-vehicle drivers in order to close at least a little of the budgetary shortfall for road maintenance in the Tar Heel State, the News Observer reports. North Carolina legislators failed to green-light a hybrid-vehicle fee of $50 a year, which may have made a little more of a dent in the state's road funding. As it is, about 1,600 EVs are registered in North Carolina, meaning that the state will collect about $160,000 in such fees this year. And while some in the state are concerned that the fee could hurt EV adoption, others say it's fair because of the $7,500 in federal tax credits EV buyers get. Oh, and the fact that EV drivers don't pay gasoline taxes. Either way, the fees are a proverbial drop in the bucket, as North Carolina's transportation shortfall is estimated to average about $2 billion a year during the next three decades or so. Other states are starting to charge EV drivers a road-use fee as well. Last February, Washington State began instituting its own electric-vehicle fee of $100 per annum, and a number of other states are considering similar policies. News Source: News Observer via EV WorldImage Credit: Copyright 2014 Sebastian Blanco/AOL Government/Legal Green Nissan Electric north carolina