Toyota brought the newest member of its Prius family to the 2012 North American International Auto Show in Detroit—the subcompact Prius c for “city,” joining its bigger brethren the third-generation Prius liftback, the Prius v, and Prius Plug-in Hybrid.
“Lighter in weight, lower in stance, and more than 19 in shorter in length, the ‘c’ is designed to maneuver the city-scape, and at 53 mpg it will offer the highest city fuel efficiency of any car in America without a plug,” said Jim Lentz, President & Chief Operating Officer, Toyota Motor Sales, U.S.A., Inc.
The c will also start under $19,000, making it one of the lowest-priced hybrids on the market and a good option for young buyers looking to get into a hybrid.
The Prius c is smaller and lighter than the midsize Prius liftback. At 157.3 in (3995 mm), it is 19.1 in (485 mm) shorter, and at 2500 lb (1134 kg), it is 542 lb (246 kg) lighter. To reduce weight and scale, and to improve efficiency, every major component of the hybrid system was redesigned and high-strength steels were used in the chassis.
“We used about three different grades of steel in the chassis, some of which is ultra-high-strength,” David Lee, Toyota Product Communications Specialist told AEI Jan. 10 at NAIAS 2012. “We tried to increase the amount of that steel in the key areas to get more rigidity, plus you also save a few pounds. We also lost a lot of weight in the hybrid driveline. Our battery weighs about 68 pounds in the Prius c, where a regular Prius liftback battery weighs in at about 92 pounds."
In addition, the transmission assembly is 15% lighter than the regular Prius's. Engine mass is reduced with a 1.5-L instead of a 1.8.
Packaging was a key focus, as components were located in places where space could be maximized.
“Our battery in the c lives under the back seat; in Prius, it’s behind the back seat and intrudes into the cargo area,” Lee said. “We bring it down low, get it under the seat, it’s out of the way. The seat support frame is also the battery module protection area.”
By locating the battery and fuel tank below the rear seat, the Prius c is able to offer 87.4 ft³ (2475 L) of passenger volume and 17.1 ft³ (484 L) of cargo volume.
The c’s drive system features a gasoline engine, electric motor within a continuously variable transaxle, nickel metal-hydride battery, power control unit, dc-dc converter, step-up converter, and a hybrid control computer. The gasoline engine and 144-V NiMH battery combine for a total hybrid system output of 99 hp (74 kW).
Separate and removed from the Prius family, Toyota also showed the NS4 (new four-door sedan) dedicated plug-in hybrid concept.
According to Lentz, the NS4 signals Toyota’s new direction in design and is the result of a challenge to Toyota engineers to design a new midsize concept for potential global market introduction by 2015.
Reductions in component size and weight are also a target of the NS4’s advanced powertrain, expected to feature improved overall fuel economy, better acceleration, and longer all-electric range while maintaining a short charge time.
On the exterior, ultra-thin A-pillars offer improved driver visibility while also maintaining roof crush integrity. The roof line profile, liftback design, and touch-to-open swan-wing doors are designed to enhance accessibility and functionality.
A solar panel roof extends into the rear hatch, and four new glass technologies currently in development are integrated into the roof, windshield, and side and rear windows.
“[These technologies] help to improve visibility, fuel economy, and the electric drive efficiency while also reducing glare and UV penetration,” Lentz said.
Conventional mirrors have been replaced by cameras that provide the driver with a panoramic view on a dedicated dashboard-mounted screen above the navigation screen.
The concept’s human-machine interface (HMI) provides a user interface built around a multi-touch screen with the look and feel of a smartphone and is capable of “learning” driver preferences and habits to anticipate driver responses in specific environments and situations.
“We see [the NS4] as a natural progression of automotive technologies by 2015,” Lentz said.