The DeSoto Fireflite III Convertible, specifically the 1959 facelift model equipped with the 6.3-liter V8 engine producing 325 horsepower and paired with a TorqueFlite automatic transmission, represents a high point in the final years of the DeSoto marque. Produced for the 1958 and 1959 model years, this iteration of the Fireflite sat at the top of the DeSoto lineup, offering a blend of luxury, performance, and distinctive 1950s American styling. It was part of the broader Fireflite range, which itself was a key model within DeSoto’s attempt to compete with the larger offerings from Chevrolet, Ford, and Plymouth.
Technical Specifications
| Brand | DeSoto |
| Model | Fireflite |
| Generation | Fireflite III Convertible (facelift 1959) |
| Type (Engine) | 6.3 V8 (325 Hp) TorqueFlite |
| Start of production | 1958 year |
| End of production | 1959 year |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet, Coupe |
| Seats | 6 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 6 kg/Hp, 165.6 Hp/tonne |
| Weight-to-torque ratio | 3.4 kg/Nm, 293.6 Nm/tonne |
| Power | 325 Hp @ 4600 rpm |
| Power per litre | 51.8 Hp/l |
| Torque | 576 Nm @ 2800 rpm, 424.84 lb.-ft. @ 2800 rpm |
| Engine displacement | 6276 cm3, 382.99 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 107.95 mm, 4.25 in. |
| Piston Stroke | 85.85 mm, 3.38 in. |
| Compression ratio | 10.1:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 4.7 l, 4.97 US qt | 4.14 UK qt |
| Coolant | 15.1 l, 15.96 US qt | 13.29 UK qt |
| Kerb Weight | 1962 kg, 4325.47 lbs |
| Fuel tank capacity | 87 l, 22.98 US gal | 19.14 UK gal |
| Length | 5616 mm, 221.1 in |
| Width | 1999 mm, 78.7 in |
| Wheelbase | 3200 mm, 125.98 in |
| Front track | 1549 mm, 60.98 in |
| Rear (Back) track | 1516 mm, 59.69 in |
| Front overhang | 889 mm, 35 in |
| Rear overhang | 1527 mm, 60.12 in |
| Ride height (ground clearance) | 142 mm, 5.59 in |
| Minimum turning circle (turning diameter) | 15.2 m, 49.87 ft |
| Approach angle | 15° |
| Departure angle | 11° |
| Ramp-over (brakeover) angle | 10.4° |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 3 gears, automatic transmission TorqueFlite |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Leaf spring |
| Front brakes | Drum, 305 mm |
| Rear brakes | Drum, 305 mm |
| Steering type | Worm-reduction unit |
Powertrain & Engine Architecture
The heart of the 1959 Fireflite Convertible was the 6.3-liter (383 cubic inch) DeSoto V8 engine. This engine, designated as the “Wedge” head due to the shape of its combustion chambers, was a significant upgrade over previous DeSoto engines. It featured a cast iron block, aluminum cylinder heads, and a hydraulic lifter valvetrain. The 325 horsepower output was achieved through a four-barrel carburetor and a 10.1:1 compression ratio. The TorqueFlite automatic transmission, a three-speed unit, was standard equipment. This transmission was known for its smoothness and durability, and it was a key selling point for DeSoto buyers who preferred the convenience of an automatic over a manual gearbox. The TorqueFlite was a push-button operated transmission, a common feature on American cars of the era.
Driving Characteristics
The combination of the 325 hp V8 and the TorqueFlite automatic provided a comfortable and capable driving experience. While not a sports car, the Fireflite offered brisk acceleration and ample power for highway cruising. The automatic transmission’s gear ratios were optimized for smooth shifts and relaxed driving. Compared to the Fireflite models equipped with the smaller 5.7-liter V8, the 6.3-liter version delivered noticeably stronger performance, particularly in passing situations. However, it wasn’t as nimble as some of its competitors, owing to its substantial weight and large dimensions. The leaf spring rear suspension provided a relatively comfortable ride, but it wasn’t as sophisticated as the independent suspension systems found on some other premium cars.
Equipment & Trim Levels
The Fireflite Convertible was positioned as DeSoto’s luxury offering. Standard features included power steering, power brakes, a deluxe interior with cloth and vinyl upholstery, full wheel covers, and a wide range of exterior trim options. Buyers could also opt for additional features such as air conditioning, power windows, a power seat, and a radio. The interior was spacious and well-appointed, reflecting the American automotive design aesthetic of the late 1950s. The dashboard featured a prominent instrument cluster with clearly marked gauges, and the steering wheel was often adorned with a horn ring.
Chassis & Braking
The Fireflite Convertible utilized a body-on-frame construction, typical of American cars of the period. The chassis featured an independent torsion bar front suspension and a leaf spring rear suspension. Braking was accomplished via drum brakes on all four wheels. While adequate for the time, the drum brakes lacked the stopping power of disc brakes, which were still relatively uncommon on American cars in 1959. The steering system employed a worm-reduction unit, providing relatively heavy but precise steering feel.
Market Reception & Comparison
The 1959 DeSoto Fireflite Convertible was generally well-received by automotive critics, who praised its stylish design, powerful engine, and comfortable ride. However, it faced stiff competition from established brands like Chevrolet, Ford, and Plymouth. The Fireflite’s higher price point compared to some of its rivals limited its sales potential. Fuel economy was typical for a large American car of the era, averaging around 15-18 miles per gallon. Reliability was generally good, but the DeSoto marque was beginning to suffer from quality control issues that would ultimately contribute to its demise.
Legacy
The 1959 DeSoto Fireflite Convertible represents a poignant chapter in American automotive history. It was one of the last models produced by DeSoto before the brand was discontinued in 1961. Today, the Fireflite Convertible is a sought-after collectible car, prized for its classic styling, powerful engine, and rarity. The 6.3-liter V8 engine and TorqueFlite transmission have proven to be relatively durable, and well-maintained examples continue to provide enjoyable driving experiences. While parts availability can be a challenge, a dedicated community of DeSoto enthusiasts ensures that these classic cars remain on the road for years to come. The Fireflite stands as a reminder of a bygone era of American automotive excess and optimism.
