The K-car platform was a key automotive design platform introduced by Chrysler Corporation in the early 1980s—featuring a transverse engine, front-wheel drive, independent front and semi-independent rear suspension configuration—a stark departure from the company's previous reliance on solid axle, rear-drive configurations. Derived from Chrysler's L-cars, the Plymouth Horizon and Dodge Omni, the platform was developed just as the company faltered in the market, at first underpinning a modest range of compact/mid-size sedans and wagons—and eventually underpinning nearly fifty different models, including all-wheel drive variants—and playing a vital role in the company's subsequent resurgence.
Arriving on the brink of Chrysler's near certain financial collapse, the platform had a dramatic effect, helping Chrysler report a profit in October 1980 of $10 million, its first profit in two years. A plethora of K-platform body styles and badge-engineered variants followed the original range, including the company's minivans and upscale Chrysler division models. The platform interchangeability saved production and purchasing costs, initially costing Chrysler $1 billion over three years to develop, but only costing $50 million to generate the second group of badge-engineered variants, the LeBaron and Dodge 400. Within two years, the K platform vehicles accounted for roughly 50% of Chrysler's operating profits.
In 1984, The New York Times said the K platform not only "single-handedly save(d) Chrysler from certain death, (it) also provided the company with a (platform) that could be stretched, smoothed, poked, chopped and trimmed."
In 1984, David Lewis, auto industry historian and professor of business history at the University of Michigan said no platform "in the history of the automobile industry has so dramatically allowed a company to survive in such a substantial way. No company has been down so low, in such difficult straits, and then depended on practically a single product to bring it back."
Following the 1973 oil crisis, compounded by the 1979 energy crisis, American consumers began to buy fuel-efficient, low-cost automobiles built in Japan. With the market for large V-8 engined automobiles declining, American domestic auto manufacturers found themselves trying to develop compact vehicles that could compete with the Japanese imports of Toyota, Honda, and Nissan in price and finish. Chrysler Corporation's answer to the import pressure was the K platform, which featured an economical 4-cylinder engine, front-wheel drive, and used many modern weight-reducing measures such as replacing metal styling parts with plastic interior and exterior components.
The K-cars (Dodge Aries, Plymouth Reliant, Chrysler LeBaron, Dodge 400, and, in Mexico, Dodge Dart) sold between 280,000 and 360,000 vehicles from 1981 to 1988, and over 100,000 in their final year, 1989.
The manual transmission provided acceleration of 0–60 mph (0–97 km/h) in 10 seconds, while the automatic was between 13 and 14 seconds, similar to or better than most competitors, while fuel economy was rated by the EPA at 26 mpg‑US (9.0 L/100 km; 31 mpg‑imp) city and 41 mpg‑US (5.7 L/100 km; 49 mpg‑imp) highway with the manual transmission. All had a 100.1-inch (2,540 mm) wheelbase. The overall length of the two- and four-door models was 176 inches (4,500 mm). The wagon was 0.2 inches (5.1 mm) longer. The vehicles had an approximate 14-US-gallon (53 l; 12 imp gal) fuel tank. The coupe and sedan had approximately 15 cubic feet (0.42 m3) of luggage space; the wagons, 35 cubic feet (0.99 m3) with the rear seat upright and about 70 cubic feet (2.0 m3) when folded down.
Numerous improvements to the sound insulation and general feel were made in 1983; in 1985, the Reliant, Aries, and LeBaron received a facelift, with a rounded front fascia, smoother hood, and bigger taillights, accompanied by fuel injection on the 2.2-liter engine and a 2.5-liter engine replacing the arguably unreliable Mitsubishi 2.6 liter engine, which was notorious for leaking oil and attracted to the cars nicknames like "Mr. Squishy" or "Bitsumishi."
They were initially very profitable, and Chrysler chairman Lee Iacocca credited them with allowing the company to pay off its bankruptcy loans early.
The first stretched-wheelbase K cars, introduced in 1983, were not given their own platform letter, but had stretched wheelbases with New Yorker styling in front: the Chrysler Executive Sedan and Limousine. They were made at the St. Louis assembly plant, and held five and seven passengers, respectively. The pair were powered by a carbureted Mitsubishi 2.6-liter four-cylinder engine coupled to the usual Torqueflite automatic transmission, though in the last two years of the Limousine, a turbocharged (but not intercooled) Chrysler 2.2-liter four-cylinder engine was added. The stretched platform was not used by Mitsubishi when they upgraded the Mitsubishi Debonair from a rear-drive sedan to front-wheel drive despite engine sharing between Mitsubishi and Chrysler at the time. Standard features included air conditioning, cruise control, power brakes, front and rear cigarette lighters, front/rear divider and rear compartment with cabinet (Limousine), rear defroster, digital instrument panel, electronic voice alert, tinted glass on all windows, hood ornament, lights that went on with the dual horn, illuminated entry, a full lighting package inside, opera lights outside, dual power mirrors, power antenna, locks, windows, and driver's seat, FM stereo, "luxury cloth" seats, tilt steering, leather steering wheel, intermittent wipers, and padded landau roof. The sedan lasted two years, while the limousine lasted four.
The K-derivatives offered a large variety of engines depending on year and model. Four-cylinder engines were initially equipped with carburetors; fuel injection was phased in beginning in the mid-1980s. Engine output ranged from 86 hp (64 kW) to 224 hp (167 kW). Most vehicles had the 2.2 l or 2.5 l Chrysler four-cylinder engine, though from 1981 to 1986 a 2.6 l four and from 1987 to 1995 a 3.0 l V6, both made by Mitsubishi, were offered. All had electronic ignition.
Use of a common platform is a common practice for reducing the number of parts and engineering time, and Chrysler, when creating the K platform, was building vehicles from a small number of common platforms (e.g. F/J/M and R). Lee Iacocca claimed that the huge number of parts in inventory and the complexity of building many completely different versions of vehicles was one reason Chrysler was losing money, and directed the engineers to focus on making a large number of common parts where they would not be visible to customers; this was already common practice in Japan and Germany and would help to make the K-cars profitable even at low prices.