The DeSoto Firesweep I 2-Door Sportsman, particularly the 1958 facelifted model equipped with the PowerPack 5.7 V8 and PowerFlite automatic transmission, represents a significant, though ultimately short-lived, chapter in the history of the DeSoto division of Chrysler Corporation. Produced from 1957 to 1958, the Firesweep was positioned as DeSoto’s entry-level full-size offering, aiming to attract buyers seeking a stylish and powerful automobile without the higher price tag of the Adventurer or Explorer models. This specific 295 horsepower configuration, paired with the two-speed PowerFlite automatic, offered a blend of performance and convenience that appealed to a broad segment of the American car-buying public.
Technical Specifications
| Brand | DeSoto |
| Model | Firesweep |
| Generation | Firesweep I 2-Door Sportsman (facelift 1958) |
| Type (Engine) | PowerPack 5.7 V8 (295 Hp) PowerFlite |
| Start of production | 1957 |
| End of production | 1958 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 6 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Power | 295 Hp @ 4600 rpm |
| Power per litre | 51.4 Hp/l |
| Torque | 522 Nm @ 2800 rpm / 385.01 lb.-ft. @ 2800 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 | 87 l / 22.98 US gal | 19.14 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 | 2 gears, automatic transmission PowerFlite |
| 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 PowerPack 5.7-liter (349.97 cubic inch) V8 engine. This engine, designated with various codes depending on specific calibration, produced 295 horsepower at 4600 rpm and 522 Nm (385 lb-ft) of torque at 2800 rpm. It featured a cast iron block and cylinder heads, with a 10:1 compression ratio. The engine utilized a single Carter carburetor, feeding into an overhead valve (OHV) valvetrain with two valves per cylinder. The PowerFlite automatic transmission was a two-speed unit, known for its smooth, but not particularly quick, shifts. It was a relatively simple design, prioritizing reliability and ease of maintenance over outright performance. The PowerFlite’s gear ratios were optimized for cruising, making the Firesweep a comfortable highway car, but less responsive in city driving or when needing quick acceleration.
Driving Characteristics
The combination of the 295 hp V8 and the PowerFlite automatic resulted in a driving experience that prioritized comfort and effortless cruising. While not a sports car by any means, the Firesweep offered ample power for merging onto highways and passing other vehicles. The PowerFlite transmission, however, limited the engine’s potential. The wide gear ratios meant that the engine often operated at lower RPMs, sacrificing some responsiveness. Compared to the manual transmission options available on other DeSoto models, or the higher-output engines found in the Adventurer trim, the Firesweep automatic felt noticeably less energetic. The leaf spring rear suspension provided a comfortable ride, but also contributed to a somewhat floaty handling characteristic, typical of American cars of this era.
Equipment & Trim Levels
The Firesweep 2-Door Sportsman, in its base configuration, offered a respectable level of standard equipment for the late 1950s. Interior appointments typically included cloth and vinyl upholstery, a basic dashboard layout with analog gauges, and a steering wheel. Optional extras included power steering, power brakes, a radio, and various trim packages that added chrome accents and upgraded interior materials. The Sportsman trim generally featured more exterior brightwork than the base Firesweep, including chrome side moldings and trim around the windows. Air conditioning was available as a factory option, a relatively luxurious feature for the time.
Chassis & Braking
The Firesweep rode on a traditional body-on-frame chassis. The front suspension utilized independent coil springs, providing a reasonably 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. Steering was handled by a worm-reduction unit, which provided relatively heavy, but predictable, steering feel. The chassis design prioritized ride comfort and durability over sporty handling.
Market Reception & Comparison
The 1958 DeSoto Firesweep, while visually appealing, faced stiff competition from other American automakers. Critics generally praised the car’s styling and comfortable ride, but noted that the PowerFlite transmission and base engine configuration didn’t deliver the performance expected from a V8-powered automobile. Compared to the more expensive DeSoto Adventurer, which offered a more powerful engine and sportier suspension, the Firesweep felt somewhat underpowered. Fuel economy, while not a primary concern for buyers in the late 1950s, was also not a strong point. The Firesweep’s reliability was generally considered average for the era, with the PowerFlite transmission being a relatively dependable component.
Legacy
The DeSoto Firesweep, and the DeSoto brand as a whole, was discontinued after the 1961 model year. The 1958 Firesweep, particularly the 2-Door Sportsman with the PowerPack V8 and PowerFlite transmission, is now a collectible classic car. While not the most sought-after DeSoto model, it represents a unique piece of American automotive history. The PowerPack V8 engine, while not known for its longevity in the same way as some other Chrysler engines, is generally considered a robust and reliable powerplant when properly maintained. Today, surviving examples are often found in restored condition, appealing to enthusiasts who appreciate the styling and character of 1950s American automobiles.
