Toyota goes its own way with green designs

TOYOTA CITY, Japan -- For a taste of future fuel-efficient styling from Toyota, go no further than the FT-HS hybrid sports car. It is counterintuitive, high-tech, and unconventional.

But global design chief Wahei Hirai says the FT-HS will form the foundation for all future styling as Toyota Motor Corp. tries to squeeze every mile from a gallon of gasoline.

The angular, low-slung FT-HS is just a concept. But its design elements already are incorporated into Toyota's iQ minicar, which will be on the streets in Japan and Europe in five months.

The new styling also will surface in upcoming hybrids, where green-conscious customers appreciate avant-garde looks.

From a design point of view, the goal is to make air-slicing cars even more slippery.

"Aerodynamics have always been important, but today they are getting more and more important," Hirai says. "We are paying very serious attention to very small details."

Four new approaches are key to Toyota's new styling trend:

1. Angular front corners for smoother airflow along the car's side.

2. A lower grille, for reduced air resistance.

3. Forward placement of the front bumper to act like an air dam.

4. Triangular, Prius-like side silhouettes for reduced drag.

The corner treatment is perhaps the most counterintuitive. Instead of using rounded front corners, Toyota is moving toward angled ones that provide a flush surface in front of the wheel. Toyota says this helps stabilize air flow and reduce turbulence around the car.

Toyota calls the treatment the Aerocorner. On the FT-HS, it is achieved by bringing the front fender forward and then making a sharp break. On the iQ, it comes from adding a corner bulge.

"What we want to do is bring the air under control before it gets to the wheelhouse," says Simon Humphries, general manager for global design. "So having a flat area and a sharp corner is actually much better from an aerodynamic standpoint than just having a round front end."

It is difficult to measure the precise benefits of the Aerocorner, but Toyota estimates that, all things being equal, it can improve a car's drag coefficient by up to 0.03 points.

Toyota is taking another unconventional step by sealing the upper front grille as much as possible and making the lower grille the main air intake for cooling the engine. The reason: a gaping hole up high causes too much drag.

Placing the grille lower not only streamlines the front fascia, but it also allows designers to make the grille opening smaller. This is because the air pressure is higher closer to the ground.

"Up until now, the upper grille has always been prioritized," Humphries says. "What we're doing here now with these cars is to change the priority, and that's quite a radical step."

The FT-HS doesn't even have an upper grille, while the iQ has a razor-thin slit.

Meanwhile, Toyota is bringing the lower bumper forward so the side silhouette is more wedge-shaped than bullet-shaped. The idea is to channel the air around the car, instead of under.

Hirai says designs also will continue to emulate the Prius-like triangular side view. That profile helps give the popular hybrid vehicle a drag coefficient of 0.26, the lowest in Toyota's fleet.

"The Prius is so good for aerodynamics, it is very difficult to change that silhouette to get something better," Hirai says. "The Prius is already very close to the best silhouette."

Nevertheless, Hirai says to expect an even lower drag resistance on the third generation of the Prius, which arrives next year.

"It has to be," he says. "We worked very hard."

Many of the new design treatments will debut in upcoming hybrid vehicles, Toyota says. After they gain acceptance from the public, the styling will migrate to other models.

"As long as these design treatments are good for aerodynamics, why not for the Prius, because the Prius has to be the leader," Hirai says. "The Prius needs a more symbolic or advanced image as an exclusive car. Sometimes those advanced designs won't be understood by everyone."

(Via: Automotive News)