The Mazda MX-03 was a four-seat, two-door high-performance sports coupe concept, unveiled by Mazda at the Frankfurt IAA show rather than the Tokyo Motor Show that had hosted its predecessors, the MX-81 (styled by Bertone) and MX-02, with its debut coming almost two months ahead of the Tokyo event. It was presented as a vision of a "high-performance sports coupe for the 1990s," combining a conservative-looking exterior with a highly futuristic interior built around a steering lever in place of a conventional steering wheel.
The body measured 451/180/120 cm (length/width/height), with a wheelbase of 271 cm and front/rear tracks of 154/151 cm, giving it proportions close to those of the Chevrolet Corvette and roughly comparable to the Porsche 928 S. A flat nose with angled headlight covers, a tapering roofline and careful aerodynamic detailing produced a drag coefficient of just 0.25, while an integrated rear wing provided downforce.
Power came from a three-rotor Wankel engine derived from the twin-rotor 13B production unit, with a chamber volume of 654 cc per rotor and a total displacement equivalent of 3924 cc. Fitting the central rotor required splitting the eccentric shaft, and the rotors were made from a light aluminum alloy for durability at high revs. A two-stage turbocharging system with ceramic turbine wheels, electronically selected according to engine speed and intake air volume, combined with an induction tract tuned for a dynamic supercharging effect, produced 320 hp at 7000 rpm and 393 Nm of torque at 3800 rpm, compared with 185 hp from the RX-7's related but smaller turbocharged two-rotor engine. A dry-sump lubrication system was used to reduce engine height. Drive went through a four-speed automatic transmission to a permanent four-wheel-drive system with a driver-adjustable torque split, controlled via a dial on the dashboard and managed by a torque sensor, control unit, oil pressure regulator and two oil-filled multi-plate clutches, eliminating the need for a central differential. Four-wheel steering, first explored by Mazda on the MX-02, used new hydromechanical control to vary rear steering angle and direction with road speed, tightening the turning circle at low speeds and steering in phase with the front wheels at higher speeds. Because there was no central differential, the ABS system was designed to disengage four-wheel drive by reducing oil pressure in the relevant clutch if a wheel threatened to lock.
Claimed performance figures included a top speed of around 300 km/h and 0-100 km/h in 5 seconds, with a target weight of 1150 kg and a 53:47 percent front/rear weight distribution. The cockpit featured a steering lever with integrated controls for wipers, lights and indicators, a head-up display, liquid-crystal instrument readouts, a safety monitor, and keyless entry operated by a handwriting-recognition system. Suspension used double wishbones and coil springs front and rear, with 7J alloy wheels fitted with 205/55 VR16 tires.
