2014 Nissan Murano 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.

U.S. auto sales fall in July, as Detroit dials back on inventory, rental sales

DETROIT — U.S. carmakers said on Tuesday they continued to slash low-margin sales to daily rental fleets in July as General Motors, Ford and Fiat Chrysler Automobiles struggled to curb a slide in retail sales. July is on track to be the fifth straight month in which the annual pace of car and light truck sales declined from the same month a year ago, in part because of fewer fleet sales, analysts and industry executives said. July 2016 sales hit a strong 17.9-million-vehicle pace. GM said the seasonally adjusted annual sales rate fell to an estimated 16.9 million vehicles in July. At midmorning on Tuesday, GM shares were down 3.4 percent at $34.77, Ford was down 2.8 percent at $10.91, and Fiat Chrysler shares were down 0.3 percent at $12.05 in New York. GM sales dropped 15 percent from a year ago to 226,107 vehicles, as the company cut rental fleet sales more than 80 percent. The automaker said inventories of unsold vehicles at month's end were 104 days, down from 105 days at the end of June. GM has promised investors to reduce inventories to 70 days by year-end. Ford said its July sales dipped 7.5 percent to 200,212 vehicles, as it cut fleet sales more than 26 percent. Inventories fell to 77 days from 79 the previous month. Fiat Chrysler said sales dropped 10 percent to 161,477, as it also cut back sales to daily rental fleets. Among the top Japanese companies, only Toyota reported a year-to-year gain, with sales up 4 percent to 222,057 — just 4,000 units behind GM. Honda sales were down 1 percent to 150,980 — its first-quarter sales continuing to decline in North America but seeing a big increase in China. And Nissan sales fell 3 percent to 128,295. GM, Ford and Fiat Chrysler have cautioned that second-half financial results likely will be lower than first-half results, in part reflecting production cuts in North America and pricing pressures. The automakers this year have been deliberately dialing back sales to rental-car companies, which often generate little to no profit, while struggling to keep retail sales from sagging further, according to industry analysts. Industry consultant LMC cut its full-year forecast for new vehicle sales to 17 million vehicles. Automakers sold a record 17.55 million vehicles in the United States in 2016.

Porsche 911 GT3 dukes it out with MP4-12C on track and GT-R on spectacular roads

The Porsche 911 GT3 has always been a favorite among auto journalists and car enthusiasts alike, but with the introduction of the new 991-generation GT3, which is the first GT3 with electric power steering and no manual gearbox option, how does it stack up to the competition from McLaren and Nissan?
Evo's Jethro Bovingdon attempts to answer that question by pitting the rear-engine Porsche against the mid-engine McLaren MP4-12C on a racetrack and the front-engine, all-wheel-drive Nissan GT-R on some amazing, twisty European back roads. We won't give away the victor of either comparison, but we will say that, in Evo's test, the McLaren's 141-horsepower advantage doesn't give it as much of an edge over the Porsche on a racetrack as one might think, and the lack of a manual gearbox and the inclusion of electric power steering on the GT3 isn't detrimental to enjoying the car on a back road.
Watch the video below to find out which car Bovingdon prefers on road and track - we think you'll be happy to see him drift around turns every chance he gets.