2009 Infiniti G37 Base Sedan 4-door 3.7l on 2040-cars

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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.

2019 Autoblog Technology of the Year finalists revealed

Every fall, we line up a range of new models with the latest and most compelling automotive technology from the past year. We test everything from semi-autonomous systems like Tesla's Autopilot to trick suspension setups like the Multimatic spool-valve shocks on the Chevy Colorado ZR2. We spend months paring down the list to a small group of contenders. After testing, dinner and healthy debate, we tally up the votes and name our winner. For Autoblog's 2019 Technology of the Year Award, our three finalists are the Cadillac CT6 with Super Cruise, the Infiniti QX50 with Variable Compression Turbo and the Mercedes-AMG E 53 with EQ Boost. Super Cruise is an advanced SAE Level 2 semi-autonomous system, though Cadillac (unlike some of its rivals) is reluctant to push that point. Cadillac would like you to think of this as an advanced driver assistance feature rather than a semi-autonomous system. Super Cruise allows completely hands-free highway driving. Thanks to a driver-facing camera, the system forces the driver to keep his or her eyes on the road even if hands are off the wheel. Although the CT6 is being discontinued, look for Super Cruise to make its way to other Cadillacs soon. VC Turbo is a little more complicated. Basically, Infiniti's 2.0-liter turbocharged inline-four can vary the compression ratio on the fly. In general, turbocharged engines are more efficient than naturally-aspirated engines when on boost, but can perform worse at low revs. VC Turbo allows for a best-of-both-worlds situation, increasing the compression at low revs and backing it off once the turbo spools up. The best part is that it does so seamlessly, with only a dash readout letting you know what's going on under the hood. Our third finalist is the EQ Boost 48-volt system in the Mercedes-AMG E 53. Like VC Turbo, EQ Boost does a lot just beneath the surface. Mercedes has developed a new turbocharged 3.0-liter inline-six and paired it with a small electric motor. While the car can't run on electricity alone, the motor helps improve both efficiency and performance, smoothing shifts and filling in low-end torque before the turbos spool up. Think torque fill, similar to a McLaren P1. Who can complain about better fuel economy and more torque? Look for the 48-volt system to make its way into most of the Mercedes-Benz lineup. The winner will be revealed next week on Autoblog, and we'll present the award Jan. 15 at the Detroit Auto Show. Related Video:

Infiniti Emerg-E Concept

The Infiniti Emerg-E is a two-place hybrid gasoline-electric concept that made its world debut at the 2012 Geneva Motor Show. While its sleek shape and stunning styling dropped jaws, those on the green side of things immediately recognized it as a reskinned and updated Lotus 414E - itself a concept based on the Evora that debuted at the same show only two years earlier. Yet there is little wrong with a reworked, Infiniti-badged Lotus boasting 402 horsepower and 738 pound-feet of torque, especially when it features a lightweight, all-aluminum bonded chassis beneath an attractive carbon fiber skin penned by the automaker's Southern California design team.
The hybrid powertrain is all contained aft of the cockpit. Primary propulsion is accomplished with two electric motors, one on each rear wheel, both featuring its own single-speed transmission (this design eliminates the need for a differential and provides electronic torque vectoring control). Energy for the electric motors is stored in a 15-kWh lithium-ion battery placed behind the seats, which is chemically different from the lithium-polymer pack Lotus used in its 414E. Auxiliary propulsion comes from a Lotus-designed, all-aluminum, 1.2-liter three-cylinder gasoline engine, rated at 50 horsepower, that serves as a range-extender after the 30-mile life of the battery pack is extinguished. Teamed with an 8.1-gallon fuel tank, the combo allows the Emerg-E to cruise about 300 miles without stopping.
Offered the chance to take the Emerg-E for a quick loop around an autocross course in Southern California, I jumped at the opportunity.