Reliant introduced a new small car at the London motor show in 1975. The mechanical parts all originated with the three-wheel Robin. Since the car weighed a mere 1,111 lb (505 kg), its 848 cc engine took it to a top speed of 80 mph. The Kitten's wheelbase was 84 in (2,140mm) with an overall length of 131 in (3,330mm). Reliant advertised the Kitten as the world's most economical car with fuel. It did about 60 miles per gallon (4.7 litres to 100 km). In 1975, the Kitten was also introduced as an estate car.
The diecast, all aluminium engine produced 40 bhp. The unit was safe up to 6000rpm, which is why 75 mph was attainable in third gear. Shift into fourth and it would cruise at 75 to 80, much to the surprise of other car drivers. Turning circle was only 24 feet.