The Jeffrey J4 was the development of customer demand for a road going version of George Jeffrey's successful 750MC specials sold between 1971 and 1972.

The J4 was very much a race going car in road going clothes. The pedigree of the J4 was obvious, looking much like a squarer Lotus Seven

The car was based around a space frame chassis and was powered mainly with Ford 1300cc or 1600cc four-cylinder engines. The J4 handled brilliantly but it had an extremely hard ride. 

The bodywork was a mix of aluminium and fibreglass paneling. The interior was sparse but functional. The J4 was superseded by the Jeffrey J5 a year later which was 'softer' and more road-going that it's predecessor.

Approximately 30 Jeffrey J4 cars were built.