The DeSoto Firesweep I 4-Door Sportsman, specifically the 1958 facelifted model equipped with the 5.7-liter V8 engine and TorqueFlite automatic transmission, represented a significant offering in the American full-size car market. Produced for a relatively short period, from 1957 to 1958, it was positioned as a stylish and comfortable family sedan within the DeSoto lineup. The Firesweep, introduced as a lower-priced DeSoto, aimed to attract buyers seeking a blend of luxury and affordability. This particular configuration, with its robust V8 and automatic transmission, was a popular choice for those prioritizing ease of driving and respectable performance.
Technical Specifications
| Brand | DeSoto |
| Model | Firesweep |
| Generation | Firesweep I 4-Door Sportsman (facelift 1958) |
| Type (Engine) | 5.7 V8 (280 Hp) TorqueFlite |
| Start of production | 1957 |
| End of production | 1958 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 6 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Power | 280 Hp @ 4600 rpm |
| Power per litre | 48.8 Hp/l |
| Torque | 515 Nm @ 2400 rpm / 379.84 lb.-ft. @ 2400 rpm |
| Engine displacement | 5735 cm3 / 349.97 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103.12 mm / 4.06 in. |
| Piston Stroke | 85.85 mm / 3.38 in. |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 3.8 l / 4.02 US qt | 3.34 UK qt |
| Coolant | 16.1 l / 17.01 US qt | 14.17 UK qt |
| Fuel tank capacity | 76 l / 20.08 US gal | 16.72 UK gal |
| Length | 5499 mm / 216.5 in. |
| Width | 1989 mm / 78.31 in. |
| Height | 1443 mm / 56.81 in. |
| Wheelbase | 3099 mm / 122.01 in. |
| Front track | 1547 mm / 60.91 in. |
| Rear track | 1516 mm / 59.69 in. |
| Front overhang | 940 mm / 37.01 in. |
| Rear overhang | 1461 mm / 57.52 in. |
| Ride height (ground clearance) | 142 mm / 5.59 in. |
| Minimum turning circle | 14.2 m / 46.59 ft. |
| Approach angle | 16.5° |
| Departure angle | 11.4° |
| Ramp-over angle | 10.5° |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine (ICE) |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 3 gears, automatic transmission TorqueFlite |
| Front suspension | Independent coil spring |
| Rear suspension | Leaf spring |
| Front brakes | Drum, 279 mm |
| Rear brakes | Drum, 279 mm |
| Steering type | Worm-reduction unit |
Powertrain & Engine Architecture
The heart of the 1958 Firesweep Sportsman was the DeSoto 5.7-liter (349.97 cubic inch) V8 engine. This engine, designated within Chrysler’s engine family as the “RB” series, featured a cast iron block and aluminum cylinder heads. It produced 280 horsepower at 4600 rpm and 515 Nm (379.84 lb-ft) of torque at 2400 rpm. The engine utilized a single Carter carburetor for fuel delivery and an overhead valve (OHV) valvetrain with two valves per cylinder. The 10:1 compression ratio contributed to the engine’s respectable power output for the era. The engine was paired exclusively with Chrysler’s TorqueFlite three-speed automatic transmission. This transmission, known for its smoothness and durability, was a key selling point for buyers who preferred the convenience of an automatic over a manual gearbox.
Driving Characteristics
The combination of the 280 hp V8 and the TorqueFlite automatic provided a comfortable and capable driving experience. While not a performance-oriented machine, the Firesweep offered ample power for highway cruising and passing maneuvers. The TorqueFlite transmission’s gear ratios were optimized for smooth acceleration and relaxed cruising. Compared to the manual transmission options available on other DeSoto models, the automatic version prioritized ease of use over outright performance. The automatic transmission did slightly diminish acceleration times compared to a manual, but the trade-off was a more refined and less demanding driving experience, particularly in city traffic.
Equipment & Trim Levels
The Firesweep I 4-Door Sportsman, even in its base form, offered a generous level of standard equipment for the late 1950s. Standard features typically included a spacious interior with comfortable bench seating upholstered in durable cloth or vinyl, a full-width dashboard with a prominent instrument cluster, and a heater. Power steering and power brakes were often included, enhancing the driving experience. Optional extras included air conditioning, a radio, whitewall tires, and two-tone paint schemes. The Sportsman trim level generally indicated a slightly more upscale interior finish compared to the base Firesweep models.
Chassis & Braking
The Firesweep rode on a traditional body-on-frame chassis. The front suspension utilized independent coil springs, providing a relatively comfortable ride. The rear suspension employed leaf springs, a common design for full-size American cars of the period. Braking was accomplished via drum brakes on all four wheels, measuring 279 mm in diameter. While adequate for the time, the drum brakes lacked the stopping power of modern disc brake systems. Steering was handled by a worm-reduction unit, which provided a relatively indirect steering feel.
Market Reception & Comparison
The 1958 DeSoto Firesweep faced stiff competition from other American automakers, including Ford, Chevrolet, and Plymouth. Critics generally praised the Firesweep’s styling and comfortable ride, but some noted that its performance was not as exhilarating as some of its rivals. Fuel economy, typical for a large American car of the era, was relatively low. Compared to other DeSoto models, such as the Adventurer, the Firesweep offered a more affordable entry point into the DeSoto brand. The Firesweep’s automatic transmission was a popular choice among buyers who valued convenience over performance, while those seeking a more engaging driving experience might have opted for a manual transmission-equipped model.
Legacy
The DeSoto Firesweep, and the DeSoto brand as a whole, had a relatively short lifespan. Production ceased in 1961 due to declining sales and internal restructuring within Chrysler Corporation. Today, the 1958 Firesweep I 4-Door Sportsman is a sought-after classic car, particularly among enthusiasts of 1950s American automobiles. The 5.7-liter V8 engine and TorqueFlite transmission, while not known for exceptional reliability compared to some later designs, are generally considered durable and relatively easy to maintain. Parts availability can be a challenge, but a dedicated network of classic car parts suppliers exists to support owners of these vehicles. The Firesweep represents a unique chapter in American automotive history, embodying the styling and engineering trends of the late 1950s.
