The DeSoto Firesweep I 2-Door Sportsman, specifically the 1958 facelift model equipped with the PowerPack 5.7 V8 engine and TorqueFlite automatic transmission, represented a significant offering in the American full-size car market. Produced for the 1957 and 1958 model years, the Firesweep occupied a middle ground within the DeSoto lineup, positioned above the entry-level Fireside but below the more luxurious Firesweep Sportsman hardtop. This particular configuration aimed to balance performance with the convenience of an automatic transmission, appealing to buyers seeking a stylish and powerful vehicle for cruising the open road.
Technical Specifications
| Brand | DeSoto |
| Model | Firesweep |
| Generation | Firesweep I 2-Door Sportsman (facelift 1958) |
| Type (Engine) | PowerPack 5.7 V8 (295 Hp) TorqueFlite |
| 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 |
| 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 this Firesweep variant was the DeSoto PowerPack 5.7 V8 engine. This engine, displacing 349.97 cubic inches (5735 cm3), was a robust and relatively modern design for its time. It featured a cast iron block and cylinder heads, with an overhead valve (OHV) configuration. The PowerPack designation indicated a higher performance version, equipped with a four-barrel carburetor and a higher compression ratio of 10:1, contributing to its 295 horsepower output at 4600 rpm and 385 lb-ft of torque at 2800 rpm. The engine’s robust bottom end and well-designed intake manifold allowed for strong low-end torque, making it well-suited for the heavy DeSoto chassis.
The TorqueFlite automatic transmission, a three-speed unit, was Chrysler Corporation’s answer to the popular Hydra-Matic. It was known for its smoothness and durability. The TorqueFlite’s gear ratios were optimized for cruising, providing comfortable acceleration and reasonable fuel economy for a vehicle of this size and weight. While not offering the driver control of a manual transmission, it catered to the growing demand for convenience in the late 1950s.
Driving Characteristics
Behind the wheel, the 1958 Firesweep with the 5.7L V8 and TorqueFlite offered a distinctly American driving experience. Acceleration was brisk, though not overtly sporty, with the engine delivering ample torque for merging onto highways and passing slower traffic. The automatic transmission shifted smoothly, but lacked the responsiveness of more modern units. The car’s substantial weight (approximately 3,800 lbs) was noticeable, particularly during cornering, where body roll was significant. The suspension, while providing a comfortable ride on smooth roads, could become unsettled on uneven surfaces. Compared to the manual transmission versions of the Firesweep, this automatic variant sacrificed some responsiveness for ease of use.
Equipment & Trim Levels
The 2-Door Sportsman trim included a generous amount of standard equipment for the era. Interiors typically featured cloth and vinyl upholstery, with a focus on comfort and spaciousness. Standard features included a full-width bench seat, a steering wheel, and basic instrumentation. Optional extras included power steering, power brakes, a radio, and whitewall tires. The 1958 facelift brought revised interior trim and exterior styling cues, including a more prominent grille and redesigned taillights.
Chassis & Braking
The Firesweep rode on a traditional body-on-frame chassis. Front suspension utilized independent coil springs, while the rear employed a leaf spring setup. This configuration prioritized ride comfort over handling precision. 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 disc brakes. Steering was handled by a worm-reduction unit, which provided a somewhat indirect feel.
Market Reception & Comparison
The 1958 DeSoto Firesweep, including the 5.7L V8/TorqueFlite combination, received mixed reviews. Critics praised the engine’s power and smoothness, as well as the comfortable ride. However, the car’s size, weight, and somewhat dated styling were points of criticism. Compared to other DeSoto models, the Firesweep offered a balance between luxury and performance. The Fireside, being the base model, was more affordable but lacked the power and features of the Firesweep. The Firesweep Sportsman hardtop offered a more stylish alternative, but at a higher price point. Fuel economy, while typical for the era, was not a strong suit, averaging around 14-16 mpg.
Legacy
The DeSoto Firesweep, and the 1958 models in particular, represent a fleeting moment in American automotive history. DeSoto, as a brand, was discontinued in 1961 due to declining sales and competition from other Chrysler divisions. Today, the 1958 Firesweep is a sought-after classic car, appreciated for its distinctive styling and powerful V8 engine. The PowerPack 5.7 V8, when properly maintained, proved to be a durable and reliable powertrain. However, finding parts can be challenging, and restoration projects often require significant investment. The combination of the V8 and TorqueFlite transmission makes it a desirable configuration for collectors and enthusiasts seeking a classic American cruiser.
