It was an exciting time for electric cars in the early 1990s. GM’s Impact concept was unveiled at the 1990 LA Auto Show, with the Tokyo Motor Show exhibiting many electric concepts as well. Among them was Tokyo R&D’s IZA. Green Car Journal editors found the IZA a fascinating counterpoint to the Impact at the time. If you’re interested in the beginnings of the modern electric vehicle field as we know it today, then there’s no better place to start then diving into Green Car Journal’s archives with us. Here, we present the following article from the Green Car Journal archives, as it was originally published in March 1992.
Excerpted from March 1992 Issue: Sleek and slippery like GM’s Impact prototype, the IZA easily garners attention from anyone in its vicinity. It did this consistently at the Tokyo Motor Show. GCJ editors there found it to be among the most formidable EV research efforts showcased by Japanese interests.
The IZA is principally sponsored by Tokyo Electric Power Company (TEPCO) as an “experimental study vehicle.” The company began with a clean slate in 1988, commissioning Tokyo R&D, Ltd. to design the body and Meidensha Corp. to handle motor and inverter development. Technical guidance was provided by the EV Research Organization and Professor Yoichi Kaya of the University of Tokyo.
Some interesting comparisons can be drawn with GM’s Impact prototype. Both aerodynamic EVs achieve an impressive 0.19 coefficient of drag, each relying heavily on wind tunnel design and high-tech construction techniques. The Impact uses a fiberglass-reinforced monocoque arrangement, while the IZA integrates a carbon fiber reinforced plastic body over an aluminum chassis. Height and width dimensions are nearly identical. Certain specifications vary widely since the Impact is a two-seater and the IZA a 2+2. The IZA’s body and wheelbase are longer (an additional 29 and 13 inches), and curb weight heftier by 1268 pounds.
One of the most interesting features found on the IZA is its brand of motivation. Meidensha Corp. integrated a direct-drive system with each wheel connected to a DC brushless motor. Japan Storage Battery Company installed 24 nickel-cadmium (NiCad) batteries to create a 288-volt, 28.8 kWh powerpack for the four-wheel drive powertrain. This battery system weighs in at a substantial 1170 pounds, one-third of the car’s overall weight. Bridgestone Ecology 205/50R17 low-rolling resistance radials were mounted to modulate road friction and unspring weight.
Endurance testing on Meidensha’s chassis dynamometer in October 1991 indicated a 343-mile range at a steady speed of 25 mph, and a 169-mile range at 62 mph. Indicated top speed is 110 mph, the same as that of the Impact.
The car incorporates a variety of comfort and convenience features including power steering, power windows, and power-assisted brakes. An inverter-controlled heat pump air conditioning system is also used. Its interior is simple but stylish, with a smoothly contoured dashboard placing all controls easily within reach. Minimal instrumentation is housed within a very small rounded cluster directly in front of the driver.
TEPCO sources advise GCJ that additional IZA models are not planned at this time. In the meantime, the company is conduction further tests and working to secure a license plate for highway operation.