Many Nissan enthusiasts regard it as a great loss that the Mid-4 concept of the late 1980’s never reached production, despite extensive development and some very favourable reviews in the media. However, the Mid-4 wasn’t Nissan’s only still-born mid engined sports car. A Decade earlier, in 1975, the Nissan AD-1 had gone on public show for the first time at the 21st Tokyo Motor Show. The AD-1 was a neatly styled, aerodynamic little two seater coupe with a mid mounted transverse engine, similar in layout to Toyota’s MR2 which wasn’t launched until some nine years later.
The AD-1 was styled with the help of wind tunnel research with a view to achieving the best aerodynamics possible, something they achieved admirably with a mere 0.26 Cd, remarkable even by todays standards. The low drag, allied to the low kerb weight of just 740kg, would have helped the car to give quite lively performance whilst still retaining a relatively small and economical engine.
In the AD-1 this was a 1.4 litre overhead valve A14 engine equipped with electronic fuel injection. Cooling the unit via long pipes to a small front mounted radiator meant the body sides could be kept free from unnecessary air intakes, whilst excess engine compartment heat was vented through grilles in the engine compartment cover behind the rear window. The AD-1 was also equipped with a 5 speed gearbox. Underneath the car was suspended by McPherson struts all round and featured duel circuit, four wheel disc brakes. Whilst today the technical details of the chassis might not seem adventurous, it was quite high specification for a small Japanese car in 1975.
Outside the car featured a luggage compartment at the rear as well as more storage under the bonnet at the front and behind the seats inside. The doors featured a simple released button with a hand cutout, rather than full door handles, similar to the design used by Renault on many models at that time. Unusually for a Japanese car of the period, the AD-1 also featured chrome, door mounted mirrors, rather than the more common fender mounted mirrors that were in use on most Japanese production cars of the day. This was possibly as a result of Nissan’s previous work with Experimental Safety Vehicles (ESV’s) as were the colour coded, impact absorbing bumpers and the well protected, mid mounted fuel tank. The AD-1 featured a lift out roof panel and a fold down rear window in a special cantilever design roof which eliminated the need for thick front pillars.
The interior of the AD-1 was functional rather than highly equipped. It’s most notable feature were the sports seats which were “infinitely adjustable” with an adjuster to alter the angle of the front of the seat squab as well as the normal recline adjuster and a separate one to change the angle of the upper half of the backrest and headrest. The frame-less door glass were open-able with manual winder handles.
The intriguing thing about the AD-1 is that although it is usually regarded merely as a styling exercise, it does appear to be an almost completely production viable car. Unlike many concept cars, it features details such as badges, locks and side repeaters… all items usually left off of concepts so as not to spoil the lines. Inside the the car looks every bit a production model and lacks the futuristic appearance seen on most concepts. It’s also likely that the AD-1 that appeared at the 21st Tokyo Motor Show was not the only AD-1 built as can be seen by the differing interiors and body colours shown in the two pictures above. This all leads one to wonder if this car was more than just a proposal? Maybe Nissan were close to building it for real, just as they were a decade on with the Mid-4? I guess we will never know for sure but either was it was probably a great opportunity lost for Nissan, especially when you consider the success of one other very similar design from the same period, the Fiat X1-9.