The FF prototype was originally a C-V8 first exhibited to the public in 1965 at the October Motor Show with another prototype car the P66 destined to be called the Interceptor. Jensen had been working with Harry Ferguson Developments since 1962 to use the Ferguson Formula 4 wheel drive system on their cars, the development being slowed due to other projects.
What Jensen managed inside the following year was outstanding by turning up at the 1966 Motor show with two completely new models: the Italian styled Interceptor and the FF. The stunning new styling of both cars allied to the FF technical specification incorporating 4 wheel drive and Maxaret anti-lock 4 wheel disc brakes made Jensen a sensation at the show.
Often mistaken visually as an Interceptor, the FF is quite a different car to accommodate the front axle and transfer box for the 4 wheel drive system and the chassis design is different with a 4” longer wheelbase. At first glance in comparison to an Interceptor there is a subtle bulge on the bonnet with a chrome finisher and slimmer dual air vents on the front wings compared to the single vent on the Interceptor. Closer examination to the front and sides of the FF reveals differences in the front panel, headlamps, grill, wing shape and bumper. From the A pillar to the rear the car is the same as the Interceptor with the exception of a larger transmission tunnel to accommodate the transfer box and centre differential.
The 330 bhp Chrysler 383ci (6276cc) V8 engine and Torqueflite 3 speed automatic gearbox is used having a master differential and chain driven transfer box mounted in place of the original output shaft. The torque output is split 37% to the front differential via a drive shaft down the left-hand side of the engine and 63% to the rear axle. The independent front suspension is unique to the FF with double wishbones, each side having twin coil springs and shock absorbers situated either side of the drive shaft. Constant velocity joints are used on the front drive shafts, the differential housing being fixed to the chassis. The Maxaret anti-lock system is incorporated into the master differential and senses differences between the speeds of the front and rear wheels, altering brake servo vacuum electrically to release braking assistance. When the speeds equal servo assistance is reapplied and the cycle starts again, pulsing being felt by the driver through the brake pedal.
Road tests at the time heaped praise on the handling and safety of the FF’s 4 wheel drive and anti-lock braking systems proclaiming it to be the worlds safest car and in 1967 Car magazine awarded the FF the Car Of The Year award. A total of 320 FFs were produced keeping inline with Interceptor development mainly in MkI and MkII bodystyles including a small number of MkIIIs until December 1971 when the FF was replaced by the two wheel drive SP as the company flagship.