Start with what the GM K platform is: a 4-door sedan with 350 CID Oldsmobile V8, built from 1975 to 1979, as the oil crises and the first emissions rules rewired the industry. What it meant takes a little longer.
How it came about
The General Motors K platform (commonly called the K-body) was the automobile platform designation used for the rear wheel drive Cadillac Seville midsize luxury models from 1975 to 1979. The rear-wheel drive K platform was based closely on the very similar 4th generation GM X platform, and 2nd generation F-bodies of the 1970s, all of which shared many components (control arms, springs, steering linkage and associated steering gear) in common. The K platform stretched the X platform to 114.3 inch wheelbase, but also improved isolation from sources of structure-borne vibration in the drivetrain and suspension. While automobiles built on these three platforms had different bodies, they shared the same unibody construction technology using a separable elastomer isolated front subframe assembly, a design which first appeared in GM vehicles on the 1st generation X platform in 1962 on the Chevy II.
Automobiles built on these three platforms (F, K, and X) also shared front and rear suspension systems, with tunings engineered to each application. The front suspensions used unequal length A-arms, coil springs damped with tubular hydraulic shock absorbers, ball joints, elastomer bushings, and recirculating ball steering boxes differing in ratios that were specific to the application. The rear suspension design used a live axle (solid axle - which was a GM corporate 10 bolt differential with an 8.5" ring gear) located by leaf springs (shared with the 1968-74 and 1975-79 X platform) damped with tubular hydraulic shock absorbers. Rear disc brakes were standard equipment in 1977 -
The hardware
The engine is 350 CID Oldsmobile V8; other versions carried different engines, listed in the specification table below. Drive goes through a 3-speed automatic. The layout matters: a front engine drives the rear wheels, the classic proportion — long bonnet, cabin set back — that most people picture when they picture a sports saloon or a grand tourer. The wheelbase is 114.3 in. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
Family and rivals
In the GM (General Motors) line-up the GM K platform has a clear place: it handed the line to the GM K platform (FWD). The cars a buyer would have weighed it against include the Hyundai Pony, the BMW 3 Series, the Volkswagen Polo. Its GM (General Motors) stablemates include the 1955 Chevrolet and the 1957 Chevrolet.
Owning one today
There is no federal ownership record for the GM K platform — it predates the complaint database or was never sold in the United States — so MotorJury publishes no running-cost figure for it. For a car of this age the price is set by the collector market and the condition of the individual example, not by a formula.