1991 Nissan 300zx Turbo Coupe 2-door 3.0l 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, Infiniti will each show a next-gen concept EV in Detroit

The chief designer for Nissan and Infiniti said Wednesday that both brands will debut concept electric vehicles at the 2019 North American International Auto Show in Detroit in January that will likely show off Nissan's next-generation electric drive systems and the evolution of the brands' EV design direction first hinted at with Infiniti's stunning Q Inspiration. Alfonso Albaisa, senior vice president of global design for Nissan, said the concepts will reflect a similar departure from standard vehicle proportions as the Q Inspiration. He would not say exactly what segment or segments the concepts would represent, but he dropped some hints at a couple possible powertrains for the concepts. Similar additional concepts will follow later in the year at the Tokyo Motor Show, he said. "The Q Inspiration kind of hinted at it and we avoided discussing too much about what's driving that car. Of course, we talked about VC-Turbo, which is also possible," he said in an interview with Autoblog. "But if you really look at the car, Q Insipiration shifted the cabin forward. It was the first one to break the [mold] of Infiniti. So how to still have this artistry and this sense of carrozzerie" (Italian for coachbuilding) "of Infiniti without kind of the stereotypical long hood and the cabin shifted back and the windshield has to go through the center of the front wheel, these golden rules." Infiniti debuted the Q Inspiration concept sedan in Detroit in January, with a swoopy, ghost-like design influenced by an archer shooting an arrow through the air, and innovative design features like an elongated cabin that expands interior space, a relative lack of chrome, and other features. It's powered by a compact variable compression turbocharged engine, which can change compression ratios on the fly to maximize efficiency and power, depending on the situation. But Albaisa said the two concepts for Detroit could feature Nissan's e-Power series hybrid technology, which has mostly featured in Japan, and which features small, isolated gasoline engines that exist only to charge the batteries, not drive the wheels. They will also feature a new generation of battery packs, which he calls a "magic carpet." "It's getting denser, it's getting thinner, the cars are able to get a little bit bigger, more space, we can really do much more," he said.

2014 Nissan Pathfinder Hybrid arrives with supercharged engine, 26 mpg combined

Nissan just launched the fully redesigned Pathfinder for the 2013 model year, and now, there's a fuel-sipping hybrid version making its debut here at the New York Auto Show. The 2014 Pathfinder Hybrid packs all of the same features found in the standard crossover, but offers slightly better fuel economy and an improved cruising range, to boot.
The new hybrid is powered by a 2.5-liter supercharged engine (we're assuming it's a four-cylinder, though Nissan hasn't specified) coupled with a lithium-ion battery and 15-kilowatt electric motor, capable of producing 250 horsepower and 243 pound-feet of torque - 10 less horsepower but three more pound-feet than the standard V6 Pathfinder. Nissan says the hybrid crossover will be rated at 25/27 miles per gallon (city/highway), with a 26-mpg combined rating. This means that on a full tank, the cruising range of the Pathfinder Hybrid is a cool 526 miles.
What's cool about the hybrid packaging is that Nissan has managed not to have it interfere with any of the interior functionality - the Pathfinder Hybrid still packs just as much cargo and passenger space as its naturally aspirated sibling. Official pricing has not been announced, but Nissan expects the hybrid to command an additional $3,000 over the standard model.