The E23 was the first of the 7-Series models. They brought a new level of power and luxury never seen before in a mass-production car. Introduced in 1977, BMW initially produced the 728 and 730 with carburettor M30 engines giving 170BHP and 184BHP respectively, the range was topped by the 733i with fuel injection and a massive 197BHP. From 1979 the engines lost the carburettors and gained horsepower, they also gained capacity with the 735i's M30 engine producing 218BHP. The most powerful E23 was only available in certain world-regions, the turbo-charged 745i's 3,210cc M30 engine produced a spectacular 252BHP.   The suspension on the E23 was radical in 1977, at the front was a sturdy MacPherson strut arrangement and at the rear was BMW's own semi- trailing link independent-suspension unit. Although the design freed up a great deal of space, the movement of the wheels and other characteristics of the suspension was less than ideal and was the source of never-ending controversy.