Mazda Takes Aim at Subaru, Snowy Climes, With Predictive AWD
Mazda isn’t the first brand you’d associate with all-wheel drive. Up until now, it’s focused tightly on its “zoom-zoom” messaging, and a reputation for lightweight, high-economy hatchbacks and sports cars.
That’s changing, now that the Japanese automaker offers a lineup of crossover SUVs, each with available i-Activ all-wheel drive. There’s the small CX-3, the mid-size CX-5, and a new version of its three-row CX-9.
The i-Activ hardware isn’t entirely new — it was introduced a few years ago with the CX-5 — yet with this new generation of crossover models now complete, Mazda is underscoring the benefits of its AWD system, which it claims has technology that makes it more efficient, and in some ways superior, versus those of established rivals like Subaru and Honda.
Mazda flew us to Crested Butte, Colorado, to demonstrate the system in ridiculously cold weather and to show off how it works. While the CX-5 and CX-9 feature the exact same hardware with slightly different software tuning, the CX-3 uses a smaller electromagnetic clutch, because the vehicle is lighter than its larger siblings.
Mazda calls its all-wheel-drive setup a part-time predictive system; it uses vehicle sensors to predict slippery situations before the vehicle’s wheels lose traction. The advantage here is that the competitor’s systems aren’t predictive — or predictive to quite the same degree, in their standard modes.
In normal driving on dry roads, the Mazda system uses an electromagnetic clutch to send one to two percent of available power to the rear wheels. (Technically, that makes it a full-time all-wheel-drive system, but Mazda calls it part-time because it’s not a big split.)
In some cases, all-wheel drive can be more efficient than front-wheel drive, even on dry roads, Mazda engineers say. The logic behind this is two-fold. On one hand it theoretically takes less energy to keep the clutch engaged than it does to disengage and reengage constantly, which introduces other factors such as mechanical backlash. The other, which comes into play in winter weather, is minimizing tire slip.
When put in a situation like going up a slick, snow-covered driveway with a curve — so the front wheels are turned — the system knows the situation based on vehicle sensor inputs and will divide the torque split more evenly from a stop, while continually modifying the front and rear torque transfer as the vehicle moves. Mazda says this is better than other systems as it’s not hunting for grip while cutting power to the drive wheels through the vehicle’s traction control system.
Mazda put us on a snowy slope and made us stop midway up the hill, to demonstrate the effect of pre-loading the all-wheel-drive system, and using the full suite of vehicle sensors to anticipate slip. Halfway up a hard-packed hill, we stopped, turned the steering wheel a full 360 degrees, then tried to climb the remainder of the path.
With all the help from sensors, the electronic controls for the all-wheel drive system are able to get a remarkably complete picture of available traction at the wheels; so the 2016 CX-5 was able to anticipate slip, sending more power to the rear wheels for a balanced launch. The wheels did slip, but the CX-5 was able to claw its way uphill, with a big boost of pre-loaded torque. Without that, it might have simply spun its wheels or worse, slid sideways into a scary situation.
Is it better than other rival systems? It’s impossible to say, without a more comprehensive test that truly uncovers the strengths, weaknesses, and flaws in all kinds of systems — like the ones found in the Honda CR-V, Subaru Forester, Ford Escape, and other crossover SUVs.
What’s changed? The fact that Mazda’s mentioned in the same sentence when it comes to all-weather traction.