The DeSoto Fireflite was introduced in 1955 as De Soto’s flagship model. The car was wider and longer than previous DeSoto models and it came equipped with a V8 engine producing 255 hp (190 kW) and PowerFlite automatic transmission. The transmission was operated by a Flite-Control lever located on the dashboard. The car weighed 4,070 lb (1850 kg) and cost US$3,544. AM radio was a $110 option.
The car was best known for its long, tapering tail fins, often accentuated by a two-tone exterior finish. The interior offered bench seating that could accommodate six passengers. The Fireflite had a 0 to 60 mph (97 km/h) acceleration time of 11 seconds and a top speed of 110 mph (175 km/h).
The Fireflite’s bold design increased sales for DeSoto. In 1955, DeSotos sold well with over 114,765 examples produced, making 1955 the best year for the company since 1946. By 1956, DeSoto placed eleventh in U.S. production with an annual production of 110,418 cars. The success was short-lived, however, and Chrysler Corporation discontinued the DeSoto brand effective in November 1960.
In 1956 a gold and white Fireflite convertible was the Official Pace Car for the 1956 Indianapolis 500. The Fireflite convertibles were rare, with only 186 produced. Indianapolis 500 President Tony Hulman said the DeSoto was chosen unanimously by the track committee because it delivered outstanding performance and had superb handling characteristics.
The 1956 Fireflite had more stroke, 3.80 for 3.30 cubic inch displacement. Compression ratio increased to 8.5:1 and power increased to 230 hp (172 kW). It made up 27.39% of DeSoto's sales in 1956. Power seats were $70, while power brakes $40.
The Fireflite’s appearance for 1957 was redesigned with the help of Chrysler Corporation's head stylist, Virgil Exner. The design was bold and radical with large tail fins, dual oval exhaust and triple-lens taillights. The tail fins were not only aesthetic, but helped to stabilize the car at high speeds.
A four-headlight system was optional for both the Fireflite and DeSoto Firedome models in 1957. The DeSoto Firesweep polyhead V8s were introduced with a bore and stroke of 3.6875 in (94 mm) X 3.800 in (97 mm). for 325 cid. The two barrel V8 was rated at 240 hp (179 kW) while the four barrel version produced 260 hp (194 kW).
The 330 cid hemi engine was replaced by a hemi which was 341 cid. The two barrel carburetor produced 270 hp (201 kW). while the four barrel version was rated at 295 hp (220 kW). Both engines had a 9.25:1 compression ratio.
In 1957 the Fireflite was superseded by the DeSoto Adventurer as the premium DeSoto model. Nevertheless, Fireflites continued to offer high-grade appointments in a full line of body styles. Also in 1957, a station wagon was added to the Fireflite's lineup. Back-up lights became standard.
In 1958, a new engine was added.
For 1959, the car was restyled. The electric clock became standard. A hand brake light was optional.