2012 Nissan Sentra 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.

IIHS: High numbers of drivers treat partially automated cars as fully self-driving

WASHINGTON — Drivers using advanced driver assistance systems like Tesla Autopilot or General Motors Super Cruise often treat their vehicles as fully self-driving despite warnings, a new study has found. The Insurance Institute for Highway Safety (IIHS), an industry funded group that prods automakers to make safer vehicles, said on Tuesday a survey found regular users of Super Cruise, Nissan/Infiniti ProPILOT Assist and Tesla Autopilot "said they were more likely to perform non-driving-related activities like eating or texting while using their partial automation systems than while driving unassisted." The IIHS study of 600 active users found 53% of Super Cruise, 42% of Autopilot and 12% of ProPILOT Assist owners "said that they were comfortable treating their vehicles as fully self-driving." About 40% of users of Autopilot and Super Cruise — two systems with lockout features for failing to pay attention — reported systems had at some point switched off while they were driving and would not reactivate. "The big-picture message here is that the early adopters of these systems still have a poor understanding of the technologyÂ’s limits," said IIHS President David Harkey. The study comes as the National Highway Traffic Safety Administration (NHTSA) is scrutinizing Autopilot crashes. Since 2016, the NHTSA has opened 37 special investigations involving 18 deaths in crashes involving Tesla vehicles and where systems like Autopilot were suspected of use. Tesla did not respond to requests for comment. Tesla says Autopilot does not make vehicles autonomous and is intended for use with a fully attentive driver who is prepared to take over. GM, which in August said owners could use Super Cruise on 400,000 miles (643,740 km) of North American roads and plans to offer Super Cruise on 22 models by the end of 2023, did not immediately comment. IIHS said advertisements for Super Cruise focus on hands-free capabilities while Autopilot evokes the name used in passenger airplanes and "implies TeslaÂ’s system is more capable than it really is." IIHS in contrast noted ProPILOT Assist "suggests that itÂ’s an assistance feature, rather than a replacement for the driver." NHTSA and automakers say none of the systems make vehicles autonomous. Nissan said its name "is clearly communicating ProPILOT Assist as a system to aid the driver, and it requires hands-on operation.

2015 Nissan Murano gets edgier, lighter for NY

Nissan's Murano stands as one of the originators of the crossover movement - it was perhaps the first such vehicle to throw out the idea that a CUV had to look like a boxy, cladded-up sport utility vehicle in order to be successful. Now poised to enter its third generation, the midsize Nissan is not only getting a new look and a host of new technologies, it's getting a new home: Canton, MS.
With dramatic new styling presaged by the Resonance Concept at last year's Detroit Auto Show, the new Murano debuting at this week's New York Auto Show includes a toned-down "V-Motion" nose, and the Japanese automaker's trademark boomerang-shaped light fixtures. Aside from the chunky chrome U-shaped grille element up front, the new Murano's most striking design detail is its cantilevered roof with funky "disconnected" D-pillars, a floating look reinforced by a greenhouse edged in brightwork. Overall, it's a much more bold and expressive piece of design than Nissan's recent second-generation Rogue, fitting, as the Murano has always been on the daring end of CUV design.
Boasting a 0.31 coefficient of drag and a ton of sheetmetal surface development, the Murano's new form is available with LED headlamps and features active grille shutters for improved aerodynamics. The company claims visibility has been improved as well - and not just because of its brilliant available Around View Monitor camera system - Nissan says it has "optimized the angles and thickness of the bottom of the A-pillar," along with fiddling with the size and location of the side mirrors.