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.

Cadillac snags de Nysschen from Infiniti, names him new president

Johan de Nysschen, the (now former) president of Infiniti, has officially jumped ship. The 54-year-old, who also spent time as the chief executive for Audi USA, has taken the position of president at Cadillac, following a two-year stint at the Nissan-owned luxury brand. In his new role, the 54-year-old will be responsible "for all aspects of Cadillac globally," according to a statement from General Motors.
"Johan brings to our company vast experience in the development and proper execution of luxury automotive brands," said GM President Dan Ammann, de Nysschen's new boss. "With over 20 years in this exact space, especially in the development of the Audi brand, his track record proves he is the perfect executive to lead Cadillac for the long term."
"I have for some time now been impressed by how the new General Motors has been transformed into a formidable force in the industry," de Nysschen said in a statement. "The combination of strong corporate leadership and exceptional engineering resources presents the perfect combination to restore Cadillac to its place among global premium brands."

NHTSA opens investigation into Nissan's handling of airbag recall

In March of 2014, Nissan recalled eight models among its Nissan and Infiniti brands, totaling more than one million vehicles, over faulty occupant classification system software controlling the passenger airbag. The company discovered a variety of factors that would interfere with the system's ability to detect an adult passenger in the shotgun seat, resulting in an illuminated warning on on the dashboard and the passenger airbag not deploying in an accident. Yet 124 complaints submitted to the National Highway Traffic Safety Administration since the recall allege that the dealer-installed fix hasn't actually fixed the problem; some consumers say the problem persists after multiple trips to the dealer. The Detroit News reports that NHTSA is opening an investigation into the matter to determine whether a new recall is needed. The occupant sensor has been a bugbear for Nissan over the past couple of years; a much smaller recall for the issue in 2013 covered five of the eight vehicles that were recalled in 2014, and that earlier recall also continued to generate complaints after the issue had supposedly been fixed. At the same time, the company learned that in two instances there was another twist, where the dashboard warning wasn't illuminated but the passenger airbag still didn't go off in an accident. Nissan isn't alone, though, with airbag recalls on a steep upswing across the industry even before the Takata debacle.