Nevertheless, for the cheaper versions of the car, BL decided to use a new six-cylinder engine which was already under development by Triumph. The rest of the drivetrain was to be shared between the SD1 and the forthcoming Triumph TR7 and TR8 sports cars. Thus the rear axle and both the manual and automatic gearboxes were designed to suit both applications.
At this was obviously carefully planned to minimize capital expenditure on production tooling, and the ruthless cost-paring which BL's planners and accountants indulged in at this period resulted in the SD1 being built down to a price. No previous Rover had ever been conceived in such a way, and the inevitable compromises caused some equally inevitable dissatisfaction among existing Rover customers who loyally bought the new car.
Despite ecstatic initial reactions from the press, and the award of European Car of the Year for 1977 by an international jury, quality control problems in the SD1's early days quickly earned the car a bad reputation. The collapse of large-car sales which followed the 1979 oil crisis then terminally damaged BL's hopes of selling the SD1 in anything like the quantities originally planned. Although vastly improved build quality, a wider model range, and a successful racing programme pulled the car round during the early 1980s, total sales never remotely approached the combined totals of the Rover P6 and Triumph saloons which the SD1 had replaced - and in fact did not even equal the totals achieved by the P6 alone.
The huge new plant which BL had built at SolihuIl for SD1 assembly never was used to the full for Rover saloons; from 1980, part of it was turned over to Triumph TR7 assembly; and then at the end of 1981 it was closed and the SD1 assembly lines were relocated in the old Morris plant at Cowley. By this stage, BL's Specialist Division had already fragmented, first into Jaguar-Rover-Triumph in the later 1970s and then even further after 1978 when Land Rover was established as a separate operating company. Rover, or what remained of it, joined the old Volume Cars division and during 1982 the resulting BL business unit took on the name of Austin-Rover.
The SD1 was undoubtedly dogged by misfortune in its early life, and it never did get the better of its direct rival the Ford Granada, let alone compete effectively with the medium-sized Mercedes and BMW saloons which made such inroads into the British market in the early 1980s. Yet for all that, it was a car with considerable character. lts striking shape remained distinctive a decade after the last example had been built; the performance and refinement of the larger-engined models were excellent; and the later cars with the full Van den Plas-specification wood and leather trim were certainly worthy heirs to the Rover name.