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How Mazda got Skyactiv-X to work is incredible

"Take everything you know about engines and turn it around," Mazda North America Vehicle Development Engineer Dave Coleman says, patiently and with a look of benevolent pity, as he's quizzed about the particulars of the company's new engine. The Skyactiv-X engine is enigmatic — and deceptively simple in operation. And the bottom line for American consumers is that they'll be able to buy a car (or crossover; we don't know yet what vehicle will first get it) by late 2019 that provides diesel-like fuel economy but runs on regular old gasoline. In between diesel and spark ignition, but it's neither To truly understand it, you have to dive into the contradictions. Take that regular old gasoline: Contrary to common sense, the lower the octane, the better it works. In the lab, the Skyactiv-X engine loves 80 octane. The lowest Americans get is 87, so the engine is tuned for that octane. Go higher and you lose some low-end torque. Coleman was right. It's hard to wrap your head around an engine that thrives just at the point when most gas engines would aggressively self-destruct. It uses a supercharger to pump additional air — but not additional fuel. It uses spark plugs to start a combustion cycle that normally doesn't need a spark. And, quixotically, it's not displacing Mazda's own American-market diesel engine, currently languishing in a seemingly endless hell of regulatory approval. More bizarre: Mazda is a tiny automaker facing real existential headwinds, and gasoline compression ignition is a massive challenge. GM and Hyundai announced compression ignition, or HCCI, projects (full name, homogeneous charge compression ignition) to great fanfare, but they never amounted to a production hill of beans, crippled by reliability issues or horrible vibrations. Worse, they only worked at an unusably narrow range — low RPMs and low loads. HCCI research improved direct-injection gas and diesel engine technologies for these companies, but HCCI itself remains untamed. The benefits of lean combustion Why even try to tame HCCI? The answer is much better fuel economy and lower emissions. Less burned carbon-based fuel, less carbon dioxide released. That's simple. But there are some thermodynamic reasons for the lean combustion you can achieve with compression ignition that are worth explaining. The ideal amount of fuel for a conventional engine to burn is about a 14:1 air-to-fuel ratio. That lets every molecule burn nicely, in theory.

Edmunds ranks the best used cars for 2013

When people ask us what car we would recommend for them, it's usually not easy to answer. To make a useful recommendation we must consider which of the numerous vehicle segments fits their needs best, and then choose one of the many vehicles offered in each segment. For some people, new cars don't meet their expectations of value, because they lose so much of it the moment they are purchased and driven off the dealer lot. For them, there's always the used-car market, where great deals can be found, but cars' histories of reliability and maintenance records - and perhaps that Certified Pre-Owned warranty - become ever-important factors playing into purchase choice.
To help out, Edmunds has done us the favor of assembling a list of the best used vehicles money can buy, covering model years 2006-2011, according to what it considers the most important criteria when shopping for used autos: reliability, safety, value and availability. That means unreliable, unsafe, super-expensive or limited-edition models don't appear on the list, but instead cars from each segment that are more likely to satisfy the general population.
There are some real goodies on the list, including but not limited to vehicles such as the capable Honda Fit, the cultish Honda Accord coupe (which can be had with a 240-horsepower V6 and a six-speed manual transmission some years), and the powerful Chevrolet Corvette. While Edmunds' choice of the Volvo C70 for best used convertible baffled us at first (not that it's a bad car), it redeemed itself by stating that the Mazda MX-5 still is an unofficial top choice if you don't require more than two seats.

2018 Mazda CX-5 gets cylinder deactivation, more standard features

Mazda recently announced its new Mazda6 would feature two engines, one of which would be a naturally aspirated four-cylinder engine with cylinder deactivation. Now the company has revealed the 2018 Mazda CX-5 will also get cylinder deactivation on its sole 2.5-liter four-cylinder. For those curious, the system shuts off the cylinders on the ends of the engine to save fuel. Mazda also says that the engine has been updated in a number of other small areas to reduce friction and further improve efficiency. The company hasn't provided fuel economy numbers for the new engine, though. The updates for the CX-5 go beyond the powertrain, as all trim levels get more standard features. The base-level CX-5 Sport now comes with a leather-wrapped steering wheel and shift knob, blind spot monitoring, and rear cross-traffic warning. The mid-level CX-5 Touring now has the i-Activsense safety feature suite standard, which includes automatic headlights, rain-sensing wipers, adaptive cruise control, lane departure warning, and lane keeping assist. This suite of features is also available as an option for the first time on the Sport model. The top-level CX-5 Grand Touring gets seat memory for two settings, as well as a power-adjustable passenger seat. These updates bring very minor increases in price. The Sport trim adds another $140 over the 2017 version. The Touring jumps the most, up $335. The Grand Touring model increases $285. You'll be able to find 2018 CX-5s soon, as Mazda says they'll be arriving at dealers December 2017. Related Video: Featured Gallery 2017 Mazda CX-5: First Drive View 25 Photos Image Credit: Mazda Green Mazda Crossover SUV mazda cx-5