The DeSoto Firesweep I 4-Door Sportsman, specifically the 1958 facelifted model with the 5.7L V8 engine producing 280 horsepower, represents a pivotal moment in the final years of the DeSoto marque. Introduced in 1957 as part of the first generation Firesweep line, the 1958 model year brought revised styling and refinements to the already popular design. Positioned as a mid-range offering within the DeSoto lineup, the 4-Door Sportsman aimed to provide a balance of style, comfort, and performance for American families. Production spanned only two years, from 1957 to 1958, before DeSoto was discontinued by Chrysler Corporation.
Technical Specifications
| Brand | DeSoto |
| Model | Firesweep |
| Generation | Firesweep I 4-Door Sportsman (facelift 1958) |
| Type (Engine) | 5.7 V8 (280 Hp) |
| 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 |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 3 gears, manual transmission |
| 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 4-Door Sportsman was the DeSoto 5.7-liter (349.97 cubic inch) V8 engine. This engine, designated within Chrysler as the “A” engine family, featured a cast iron block and aluminum cylinder heads. The 280 horsepower output was achieved through a four-barrel carburetor, a 10:1 compression ratio, and a relatively high 4600 rpm peak power point. The engine utilized an overhead valve (OHV) valvetrain with two valves per cylinder. The 5.7L V8 was known for its robust construction and relatively simple design, making it fairly reliable for the era. The standard transmission for this model was a three-speed manual gearbox. While an automatic transmission was available on other Firesweep models, the 280 hp version was primarily offered with the manual, catering to drivers who preferred more control.
Driving Characteristics
The 1958 Firesweep with the 5.7L V8 and manual transmission offered a spirited driving experience for the time. While not a sports car, the 280 horsepower provided ample power for highway cruising and passing maneuvers. The three-speed manual gearbox allowed drivers to fully utilize the engine’s torque curve. Compared to the lower-powered DeSoto models, the 5.7L version felt significantly more responsive. However, it wasn’t as refined or powerful as the larger Chrysler engines available in other vehicles within the Chrysler Corporation portfolio. The leaf spring rear suspension provided a comfortable ride, but it wasn’t particularly sophisticated in handling. The car’s substantial weight (approximately 3,700 lbs) meant that cornering was best approached with caution.
Equipment & Trim Levels
The Firesweep 4-Door Sportsman was well-equipped for a 1958 vehicle. Standard features included a spacious interior with comfortable bench seats upholstered in durable cloth or vinyl. The dashboard featured a full-width instrument panel with prominent gauges for speed, fuel, temperature, and oil pressure. Exterior styling included generous chrome trim, distinctive tailfins, and two-tone paint options. Optional extras included power steering, power brakes, a radio, and whitewall tires. The “Sportsman” designation indicated a slightly more upscale trim level compared to the base Firesweep models, often including upgraded interior materials and additional chrome accents.
Chassis & Braking
The Firesweep rode on a traditional body-on-frame chassis. The front suspension utilized independent coil springs, providing a relatively smooth ride. The rear suspension employed leaf springs, which were common for American cars of this era. Braking was accomplished via drum brakes on all four wheels, measuring 279mm in diameter. While adequate for the time, the drum brakes lacked the stopping power and fade resistance of modern disc brakes. Steering was handled by a worm-reduction unit, which provided a somewhat indirect steering feel.
Market Reception & Comparison
The 1958 DeSoto Firesweep received generally positive reviews from automotive journalists. It was praised for its stylish design, comfortable interior, and strong V8 engine. However, critics also noted the car’s substantial size and weight, as well as the somewhat dated technology compared to some of its competitors. Compared to other DeSoto models, the 5.7L V8 version offered a noticeable performance advantage. It competed with other mid-size American sedans from Ford, Chevrolet, and Plymouth. The Firesweep’s fuel economy was typical for the era, averaging around 15-18 miles per gallon. Reliability was generally good, although the carburetor could require occasional adjustments.
Legacy
The DeSoto Firesweep, and the 1958 facelifted version in particular, holds a special place in automotive history as one of the last models produced by the DeSoto division. The 5.7L V8 engine proved to be a durable and reliable powerplant, and many examples are still on the road today. In the used car market, well-maintained Firesweeps are sought after by collectors and enthusiasts who appreciate their classic styling and vintage charm. While parts availability can be a challenge, the engine’s relatively simple design makes it relatively easy to repair and maintain. The 1958 Firesweep serves as a reminder of a bygone era of American automotive design and engineering.
