Turbo – Cars with Turbo (Garratt T3) and Dell'orto Carburettors (early cars had twin 40's and later cars had twin 45's)

HCPI – Cars with Turbo and Bosch 'K' Jetronic Fuel Injection (compression ratio was increased hence the HC)

GMP4 – Cars with General Motors (GM) Fuel Injection (Delco Electronics ECU)
GMP4 – Similar Engine spec to HCPI but with more sophisticated control system to meet stricter USA emissions requirements
GMP4 – (has on board diagnostics ability)

INTRCL – Cars with GMP4 Injection and fitted with an Intercooler (water to air) to increase Power.

From Lotus
'As for production figures for HC Giugiaro we are looking at a figure of 308 which will also include Bosch injected cars but it is difficult to give an accurate breakdown of how many were non injected.