Downsizing in the automobile industry is the practice of redesigning a vehicle to retain the interior volume, and often the nameplate and styling of a larger car to a smaller, more efficient platform. It was common in the 1970s following the 1973 oil crisis.
General Motors was among the first to announce a downsize strategy for the whole company as a response to demand for smaller more efficient cars. An alternative strategy was to simply rebadge or mildly restyle smaller vehicles, as nameplates such as the Ford LTD and Plymouth Fury were applied to smaller platforms.
The term engine downsizing is used when the car itself remains the same size but the engine is reduced, with the aim of making the vehicle more efficient.
The University of Bath published research carried out by its Powertrain and Vehicle Research Centre which demonstrated that it is possible to reduce engine capacity by 60% and still achieve the torque curve of a modern, large-capacity naturally-aspirated engine, while encompassing the attributes necessary to employ such a concept in premium vehicles.
From 1977 to 1982, in order, General Motors would physically downsize its full-size, intermediate, compact, and subcompact vehicle product lines in the process of vehicle redesigns. For 1977, all five GM car divisions ( Buick, Cadillac, Chevrolet, Oldsmobile, and Pontiac) saw the downsizing of their full-size vehicle lines, with an average length reduction of 12 inches and 750-800 pounds in weight (with over 1000 pounds in some examples). While producing a smaller exterior footprint than the GM intermediate product lines, the full-size cars would see similar interior dimensions as their predecessors. For 1978, the GM intermediate product line (based on the GM A platform) became true mid-size cars with similar size reductions.