The Lincoln K Series is a range of luxury cars built by Lincoln and first introduced in 1931. The K Series was the top of the line model for the Lincoln range, and was available in two main variants, the Model KA and the Model KB. Originally, the KA was fitted with a V8 engine while the KB was fitted with a V12, but soon all K Series cars were fitted with V12 engines, making KA and KB the designation for wheelbase length. The K Series was available in a variety of body styles, including roadster, coupe, phaeton, and sedan. Coachbuilt versions of the K Series were also common. The Lincoln K Series was in production until 1940.