Subaru is known primarily for two things: their symmetrical all-wheel drive system and their use of flat Boxer engines. And now hybrids? It’s not surprising that Subaru should thrwo their hats into the hybrid market, as that’s what pretty much every car company is doing nowadays, but it is nice to see that Subaru will not sacrifice any of their heritage in order to bring extra electricity to their unique vehicles.
Let’s begin with the all-wheel drive system. It’s a feature that Subaru has prided itself on for years and, if you live in an area that has rough winters, it has also been highlighted extensively in their advertising. The Hybrid Tourer continues that feature by having two electric motors, one at the front and one at the rear. The front motor, which is rated at 27 horsepower, also doubles as an electric generator, so when you apply the brake, the motor acts as a drag brake, which will slow the car and produce electricity.
In fact, the varied functions of the three different drive systems, the engine and the two electric motors, makes this car less of a hybrid and more of a tri-powered car. When you drive at very low speeds, like pulling out of your driveway or in stop-and-go traffic, the rear electric motor, rated at 13 horsepower, provides pretty much all of the drive. When you accelerate, the gas engine and the rear electric motor work together, and then the electric motor cuts out once you’re at normal cruising speeds, at which time the gas engine does all the work. If, however, you are accelerating uphill, which requires more force, and hence more gas, the front electric motor will kick on to help out. Most of the time, the front electric motor will act as a regenerative brake. If that sounds complicated, don’t worry, because the Tourer’s onboard energy management computer (which has undergone extensive testing in Subaru’s STELLA plug-in concept) is great at its job. It’ll cut the gas engine off when idling to conserve fuel, and the initial acceleration from the rear electric motor will cover the restart of the gas engine when you push on the accelerator. In fact, aside from engine noise, you won’t even notice the system doing its work.
The gas engine under the hood is a fairly standard 2.0-liter turbocharged flat four-cylinder Boxer, an engine found in many Subarus on the road today. It has been tweaked to provide more fuel efficiency, but other than tuning, it’s essentially unchanged. What it’s connected to, though, is reason for excitement. Subaru is unveiling the Lineatronic automatic transmission on the Hybrid Tourer. This transmission is a CVT (Continuously Variable Transmission) meaning that instead of traditional gears, it has an infinite number of potential drive ratios, so it can always provide a quick and efficient means of acceleration and speed maintenance. And, because it essentially has a special “gear” (though it’s realy just a position along the variable path) for any situation, that increases fuel efficiency by a fair amount (no official numbers, but an estimate is about 8%) all on its own.
As far as styling goes, the Hybrid Tourer Concept is both indicative of Subaru’s future hybrid products (which are slated for wide release in the 2011 model year) and not so indicative. The large gullwing doors, for example, will unfortunately not make their way to production. Subaru chose them for the concept for two reasons: first, they’re a real eye-grabber; and second, they allow an unobstructed view into the cabin. And one of the cabin features they really wanted to emphasize was the flat floor. The placement of the rear electric motor and batteries don’t interfere with the cabin’s space. After all, the regular hump in between the front seats, and the rears, was a result of engineers needing a place to put the drive shaft and transmission. Hybrid cars, due to separate drive systems that are connected only by wires, don’t need the extra space.
The final fancy bit of technology packaged into the Subaru Hybrid Tourer is called EyeSight. As the name implies, this system is designed to help drivers get a better view of their surroundings. EyeSight uses a stereo-camera system and a 3D-processing computer to essentially build a 3d representation of the environment surrounding the car, including other vehicles on the road, and will alert drivers when cars get into their bind spot or other problem areas. While it remains to be seen just how useful the system will be in real-life situations (it’s still relatively new), and whether or not it will be cost effective compared to other blind spot detection systems, the idea behind the device is novel and could turn out to be a great invention.
The Subaru Hybrid Tourer Concept is essentially a big preview of what’s to come from Subaru in the next few years. The styling cues on the Tourer retain the feel of other Subaru models, while also portraying a more streamlined and sophisticated design. The Hybrid drive system is exciting, but its success will really rest on the energy management computer and the seamlessness of the ride quality when switching between drive systems. And EyeSight seems more like a safety gimmick than a truly exciting piece of tech. So, while we’ll have to wait until 2011 to see how things pan out, the Hybrid Tourer Concept shows that Subaru is definitely on the right path.