1999 Infiniti Q45 T Sedan 4-door 4.1l on 2040-cars

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2019 Infiniti QX50

The 2019 Infiniti QX50 has arrived. All new engine and a whole lot of new technology.

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.

Race Recap: Singapore Grand Prix is about a safety car and submission

The Singapore Formula One Grand Prix is the Monaco GP of the Orient - a weekend known more for its glamour and time-slot than on-track action, with a temporary circuit that punishes every mistake, usually terminally.
Lewis Hamilton in the Mercedes-AMG Petronas got the best of Free Practice 1, opening the curtain on a possible resurgence of Silver Arrows performance. By the time qualifying was done, though, it was his teammate Nico Rosberg who lined up second on the grid, followed by Romain Grosjean with a beautiful performance in the Lotus, Mark Webber in the Infiniti Red Bull, and Hamilton all the way back in fifth. Behind them were Felipe Massa outqualifying Ferrari teammate Fernando Alonso, Jenson Button getting the McLaren into eighth, Daniel Ricciardo with another good Q3 effort to get into ninth, and the shocker of Esteban Gutiérrez getting his Sauber into the top ten for the first time this year.
At the front of the pack was Sebastian Vettel. Again. But he was only ahead of Rosberg by a single tenth of a second...