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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 gives good ratings to 4 of 8 midsize pickups in crash test

Versions of the Toyota Tacoma, Chevrolet Colorado and GMC Canyon Crew Cab earned top ratings in a new crash test of midsize pickup trucks from the Insurance Institute for Highway Safety, while two versions of the Nissan Frontier earned marginal ratings. But the organization gave poor marks to all eight pickups tested for their dim headlights. Overall, four of the eight pickups evaluated earned good ratings for protecting occupants in all five crash test categories — the Tacoma double cab along with crew cab versions of the Colorado, Canyon and Tacoma. But the poor headlights and lack of an automatic emergency braking system blocked any of the pickups from qualifying for the IIHS's Top Safety Pick awards. The study looked at two pickup body styles using 2017 models: crew cabs, which have four full doors and two full rows of seating, and extended cabs, which have two full front doors, two smaller rear doors and compact second-row seats. It subjected each to five tests, and it evaluated the performance of front crash prevention systems and headlights. The Toyota Tacoma crew cab was the only pickup in that class that earned a good rating for structure in the small overlap test, which replicates what happens when a vehicle clips a tree, pole or another vehicle that has crossed the center line. The model's Access Cab extended-cab version was rated similarly, though its structure was rated acceptable. "This group of small pickups performed better in the small overlap front test than many of their larger pickup cousins," says David Zuby, the Institute's executive vice president and chief research officer. "The exception was the Nissan Frontier, which hasn't had a structural redesign since the 2005 model year." The extended-cab versions of the Chevy Colorado and GMC Canyon earned acceptable ratings, while both the Nissan Frontier king-cab and crew-cab models were rated marginal. Toyota says its 2018 Tacoma will feature upgraded headlights and a standard autobraking system that can detect pedestrians. "Headlights are basic but vital safety equipment. Drivers shouldn't have to give up the ability to see the road at night when they choose a small pickup," Zuby said. Related Video: Auto News Chevrolet GMC Nissan Toyota Safety Truck Videos gmc canyon nissan frontier chevrolet colorado

2015 Nissan Versa Sedan continues to prioritize space and price over looks

Nissan's refresh of its cavernous Versa Sedan is on hand today at the 2014 New York Auto Show. While we continue to appreciate the Versa for its space and low price, this slight restyling of the four-door sedan hasn't done much for its uninspiring appearance.
Newly enlarged headlights and a reworked, more Altima-like grille are the biggest changes to the front of this Versa, although Nissan has also added some brightwork around the revised foglight housings. Integrated turn signals liven up the mirrors, while the rear of the car wears a new and almost strangely sporty bumper.
Perhaps more importantly for prospective owners, Nissan has also made a few interior tweaks, with a new steering wheel and a revised center stack leading the change. There's some new available tech on the top-end SL model, as well.