One of Spen King's first projects for BL Technology to be seen by the public. Looking at energy efficient vehicles and Energy Conservation Vehicle 2 (ECV2) was the first seen by the public. ECV2 managed 60mpg - impressive for 1981.

Its successor, ECV3, was completely new. ECV3 was very light having an Alcan aluminium frame, clothed in unstressed plastic panels with bonded windows. With a very low drag co‐efficient of just 0.24Cd, it had room inside for four, the equivalent space to a larger car.

With a one litre, three cylinder, fuel injected, single OHC engine, it could reach 115mph but also average over 100mpg. ECV3 was revolutionary and many of its features made their way into future car technology.