The vehicles also exceed the MLIT fuel efficiency standard for 2015 by 20% and achieve emissions levels 75% lower than the 2005 standards under the MLIT's Approval System for Low-Emission Vehicles, making them eligible for tax reductions under the Japanese government’s tax incentive program for environment-friendly vehicles.

The vehicles feature the fuel-efficient Atkinson-cycle engine, as well as a cooled Exhaust Gas Recirculation (EGR) system to further improve engine efficiency.

The water pump is driven by an electric motor, thus eliminating the need for a drive belt. Not only is friction loss reduced, coolant flow rate can be very precisely controlled, contributing to improved fuel economy.

The NiMH hybrid battery is placed under the rear seat for more efficient use of interior space. Rear seat knee space is 640 mm, achieving comfort on par with gasoline-engine vehicles. Luggage space is also comparable to gasoline-engine vehicles, with the Corolla Axio possessing 461 liters and the Corolla Fielder possessing 407 liters when carrying five passengers and 872 liters when carrying two passengers.

Suspension and shock absorber settings were adjusted to accommodate the increased weight and lower center of gravity of the hybrid system. The use of additional sound insulation material and noise-reducing windshield glass further enhances cabin quietness.

Two drive modes come standard: the Eco-Drive Mode that gives highest priority to fuel economy and the EV Drive Mode for using only the electric motor.

Also standard is a Vehicle Proximity Notification System designed to warn pedestrians—and other people in the immediate vicinity of the vehicle—of the approach of a quiet hybrid car, and the Hill-start Assist Control function that is designed to prevent the vehicle from rolling backwards.

Starting price for the Axio Hybrid is ¥1,925,000 (US$19,589); starting price for the Fielder Hybrid is ¥2,085,000 (US$21,217).