Mazda tech brings out inner geek
I’m not sure if this will come as a surprise or not but I am, at heart, a geek. Oh, sure, a lifetime’s worth of domestication has seen me eschew pocket protectors and I take extra precautions whenever I decide to forego my normally uni-colour black wardrobe for something more pastel-ly. Nonetheless, hit broadside with a surprise new widget for my iPad or the definitive explanation of the thermodynamics of turbocharging, I will start fluttering about excitedly like Sheldon Cooper, the über-geek physicist on The Big Bang Theory.
Which is what happened at the Mazda press meeting that predated last week’s Toronto auto show. There I was, bored out of my mind listening to what I thought would turn out to be mostly public relations bumpf — something Mazda is calling SKYACTIV, which sounded to me like a marketing campaign some underemployed MBA dreamed up — when Robert Davis, the company’s senior vice-president of quality, research and development, hit me with “and our i-stop system [Mazda’s name for its start-stop mechanism that shuts down the motor at stoplights] doesn’t even use the starter motor to restart the engine.”
Huh? And there, before I could regain any sense of composure or objectivity, I transformed from a 53-year-old bored reporter into a 13-year-old car geek determined to go through the Sept-Iles library’s entire stock of technical manuals in search of automotive truth. What? When? Why? How? I don’t think any of the other reporters got a question in edgewise. So, don’t say I didn’t warn you: This is about to get nerdy.
It turns out that, unlike every other stop/start system I’ve tested that saves gas by shutting the engine down at stoplights and then uses the starter to reactivate it once the driver releases the brake pedal, Mazda’s i-stop uses the engine’s own compression to restart the motor.
Here’s how it works: When the car arrives at the stoplight, one cylinder stops just past top dead centre on the compression stroke. That means one of the cylinders is in the full go mode; the charge is compressed and the piston is in ideal position for combustion. When the driver releases the gas, the computer — rather than activating the starter motor — injects fuel into that specific cylinder while simultaneously firing the spark plug and lets the normal combustion process start the engine. It reduces energy consumption and means Mazda doesn’t have to beef up the engine compartment with a bigger, heavier starter motor.
Of course, if an enhanced start/stop function were the highlight of Mazda’s latest technological enhancements, then SKYACTIV would simply be a marketing ploy. But according to Davis, there’s much more to Mazda’s future than the starter-less, er, starting. For one thing, its not all about motors. As I’ve previously detailed, one of the biggest challenges automobile manufacturers face in their quest to boost fuel economy is reducing weight. Not only does having less weight to lug around improve fuel economy directly, but it can also mean that the same car can have a smaller engine, further enhancing fuel consumption without sacrificing performance.
The problem, of course, is doing so without forfeiting passenger comfort and safety as well as holding costs in line. According to Davis, Mazda plans to reduce the weight of each of its models by 100 kilograms every time a major redesign is undertaken. More importantly, it will do so with cost-effective engineering advancements such as air-pressurized aluminum extruding (even my inner didactic dweeb didn’t understand that one) rather than relying on exotic and, therefore, expensive, alternative materials.
Perhaps the most interesting aspect of Mazda’s plans is that, unlike most other manufacturers, its immediate future will not be electrified. Yes, the company is developing EVs, but Davis sees the majority of the improvement (up to 15% higher efficiency in the next eight to 10 years) to worldwide fuel consumption coming from advancements to the good, old-fashioned internal-combustion engine.
We’ll start seeing some of those developments immediately, says Davis, as Mazda will start building its gas engines with compression ratios of up to 14:1. That might not get everyone’s heart racing, but to true automotive dorks, it’s something of a holy grail. High-compression ratios are the main reason diesel engines are more frugal than gasoline-fuelled motors. As a gas engine’s compression ratio approaches that of an oil burner’s, however, so, too, will its fuel economy, all without the inherent disadvantages of diesel combustion.
That Davis claims Mazda’s high-compression motors will run on regular octane gas thanks to some trickery with variable valve timing is just another reason my inner dork was celebrating.
All told, Davis expects that Mazda can manage a 30% decrease in fuel consumption by 2015 without changing the basic design or performance of its cars. I, for one, hope his message of efficient engineering is one that is heard above the din of hybrids and EVs.