1958 DESOTO - GENERAL: 1958 DeSoto styling was a minor facelift from the 1957 models. Changes included a honeycomb grille insert, a dip in the center of the middle grille bar and round parking lights at the outboard ends of the lower grille opening. Dual headlamps were standard on all models.

For the first time, Fireflite, Firedome and Firesweep all offered an expanded model line including convertibles, hardtops and 4-door sedans, less station wagons. Wagons were only available in the Fireflite and Firesweep line. Eighty-six two-tone and 14 solid color schemes were offered for 1958.

Biggest news was the introduction of the new "B" Series corporate V-8 engine used across all lines except Chrysler.

INNOVATIONS: The new "B" series V-8 with wedge-shaped combustion chamber-head. It was the first of the new generation "corporate" V-8s, available in 350 and 361 CID the new cylinder heads and the distributor in the front of the engine for easier service. A full-flow oil filter was standard. which featured a rigid, deep-skirt block; in-line overhead valves employing a single shaft in each cylinder head. It's weight dropped to 640 pounds; less than the DeSoto-only Hemi it replaced. DeSoto, Dodge and Plymouth shared the new engine, with Chrysler continuing to use their big 392 CID Hemi.

1958 FIRESWEEP SERIES LS1-L (8-Cylinder wedge-head V-8):  This series continued to use the Dodge chassis. Body side trim was redesigned so that the upper molding ran at an angle to the upper corner of the tailfin. There were "Firesweep" rear fender nameplates, and a continuous band of metal decorated the front lip of the hood and climbed over the headlamp hoods. Firesweep Sportsman models had the dome-like windshield seen on 1957 convertibles, while sedans continued with a visored windshield header.

An upgraded interior, matching those in the Firedome could be had in selected Firesweep models at extra cost., Electric windshield wipers were employed and the new "B" Series 350 CID V-8 wedge engine was fitted. A Power Pack, 4-barrel carburetor option was available.

1958 FIREDOME SERIES LS2-M (8-Cylinder wedge-head V-8): The Firedome was basically unchanged for 1958. "Firedome" nameplates were placed on the rear fenders. All Firedome models had the same side trim as the lower priced Firesweeps, but the front molding treatment was different. "Windsplit" ornaments for tops of front fenders were an option.

The interior was upgraded over the Firesweep. Upholstery materials were defined as "Frontier Homespun" fabric (cowboys were a big thing in 1958) in combination with grained vinyl, all colored to harmonize with exterior finish. Firedomes used the new "B" series V-8 but with an increased displacement to 361 CID.

1958 FIREFLITE SERIES LS3-H (8-Cylinder wedge-head V-8): The top rung DeSoto series was identified by "Fireflite" rear fender nameplates and a distinctive upper body side molding which extended the full length of the car and incorporated special medallions on sides of front fenders. "Windsplit" fender-top ornaments were standard equipment. "Color Sweep" trim was standard on hardtops and convertibles.

Fireflite interiors were a step up from the Firedome and leather was an option on some models. The Fireflites used the same new "B" series 361 CID V-8 as the Firedome, but fitted with a 4-barrel carburetor. 

A springtime trim package was released as an option for all models except Adventurers, and featured two groups of four vertical bright metal deck lid slashes affixed one group to each side of the recessed license plate housing. New exterior colors were announced about the same time. Fireflite interiors were done in metallic Damask and vinyl and incorporated integrated arm rests with aluminum finish recesses above.

1958 ADVENTURER SERIES LS3-S (8-Cylinder wedge-head V-8): The Adventurer models were still a Fireflite sub-series, but pure performance and luxury. Like the Fireflites, these high-performance cars came standard with Torqueflite transmission, backup lamps and full wheel covers, but there were some other extras that were standard: power brakes, dual exhausts, dual rear radio antenna, dual outside rear view mirrors, white sidewall tires, dashboard safety panel and special paint and trim. The latter included gold highlight surrounds, twin groupings of four deck lid bars, triangular rear side sweep inserts and special upholstery.

The Adventurer also used the same new "B" series 361 CID V-8, but was fitted with dual 4-barrel carburetors, and a camshaft upgrade but no cylinder head/valve increases over the Fireflight. It was rated at 345 HP.  A radical new option was an electronic fuel injection system manufactured by Bendix which increased the output to 355 HP. Cars with fuel injection had special nameplates above the front fender medallions. Most were later recalled to the factory and converted back to Adventurer "standard" dual-quad carburetors due to the fuel injection system's unreliability.

MODEL/ENGINE I.D. DATA:

• Firesweep serial numbers: Cars built in Detroit had serial numbers that ran fromLS1-1001 to 18900. Cars built in Los Angeles had serial numbers from LS1L-1001. Motor numbers ran from L350-1001.
• Firedome serial numbers. Cars built in Detroit had serial numbers that ran from LS2-1001 to 17409. No cars were built in Los Angeles. Motor numbers ran from L360-1001 and were interspersed with Fireflite engines.
• Fireflite serial numbers. Cars built in Detroit had serial ran from LS3-1001 to 13552. No cars were built in Los Angeles. Motor numbers ran from  L360-1001 and were interspersed with Firedome engines.
• Adventurer serial numbers. All Adventurers were built at the Detroit factory. Adventurer Serial numbers ran from LS3-1001 to 13552 and  were interspesed with Fireflite serial numbers.  Motor numbers ran from  L360-1001 and were interspersed with Firedome and Fireflite engines.

Serial number codes were on  the left front door hinge pillar post. V-8 the engine numbers were positioned at the top of the engine block under the water outlet elbow. No code numbers were provided for positive identification of body style type.

BODY PAINT CODE/COLORS:

• A Black 
• B Wedgewood Blue
• C Haze Blue
• D Midnight Blue
• E Willow Green
• F Spruce Green
• H Seacoast Aqua
• J French Turquoise
• K Arctic Gray (Firesweep)
• K Smoke Gray
• L Cruiser Gray (Firesweep)
• L Steel Gray
• M Rose Beige (Firesweep)
• Sand (Firesweep)
• O Autumn Rust
• P Holly Red
• R Persimmon Red
• S Spring Rose
• U Sand Dune Yellow (Firesweep)
• U Spanish Gold
• V Adventurer Gold
• W Heather Blue
• X Pearl White

DESOTO ENGINES:

• DeSoto Firesweep V-8. Overhead valves. Cast iron block. Displacement: 350 CID. Bore and stroke: 4.06" x 3.38". Compression ratio: 10.0:1. Horsepower: 280 @ 4600 RPM. Torque: 380 @ 2400 RPM. Five main bearings. Hydraulic valve lifters. Carburetor: Manual Trans - Ball & Ball two-barrel BBD 2772S; Auto Trans - Ball & Ball two-barrel BBD 2637S.
  
  
• DeSoto Firesweep Power Pack V-8. Overhead valves. Cast iron block. Displacement: 350 CID. Bore and stroke: 4.06" x 3.38". Compression ratio: 10.0:1. Horsepower: 295 @ 4600 RPM. Torque: 385 @ 2800 RPM. Five main bearings. Hydraulic valve lifters. Carburetor: Manual Trans - Carter AFB four-barrel 2773S; Auto Trans - Carter AFB four-barrel 2642S. Dual exhausts as standard equipment.
  
  
• DeSoto Firedome V-8. V-8. Overhead valves. Cast iron block. Displacement: 361 CID. Bore and stroke: 4.12" x 3.38". Compression ratio: 10.0:1. Horsepower: 295 @ 4600 RPM. Torque: 390 @ 2400 RPM.  Five main bearings. Hydraulic valve lifters. Carburetor: Manual Trans - Ball & Ball two-barrel BBD 2772S; Auto Trans - Ball & Ball two-barrel BBD 2637S.
  
  
• DeSoto Fireflite V-8. Overhead valves. Cast iron block. Displacement: 361 CID. Bore and stroke: 4.12" x 3.38". Compression ratio: 10.0:1. Horsepower: 305 @ 4600 RPM. Torque: 400 @ 3600 RPM.  Five main bearings. Hydraulic valve lifters. Carter Four-barrel AFB 2642S. Convertible equipped with Dual Exhausts - optional others except wagon.
  
  
• DeSoto Adventurer V-8. Overhead valves. Cast iron block. Displacement: 361 CID. Bore and stroke: 4.12" x 3.38". Compression ratio: 10.25:1. Horsepower: 345 @ 4600 RPM. Torque: 400 @ 3600 RPM.  Five main bearings. Hydraulic valve lifters. Carburetors: two four-barrel Carter AFB - front number 2652S; rear number 2653S.
  
  
• DeSoto Adventurer Optional Fuel Injected V-8. Overhead valves. Cast iron block. Displacement: 361 CID. Bore and stroke: 4.12" x 3.38". Compression ratio: 10.25:1. Brake horsepower: 355 @ 5000 RPM. Torque: 400 @ 3600 RPM.  Five main bearings. Hydraulic valve lifters. Induction: Bendix Electronic Fuel Injection.

These cars were originally built with dual-quad carburetors and were then converted to fuel-injection at the DeSoto factory. Most were later returned to the two 4-barrel configuration due to the fuel injector system's electronic malfunctions.

CHASSIS:

• Wheelbase: Firesweep 122". All others 126".
• Overall length: Firesweep station wagon 218.1". Firesweep passenger cars 216.5". Firedome, Fireflite and Adventurer 218.6". All other station wagons 220.2".
• Front tread: Firesweep 60.9". All others 61".
• Rear tread: All 59.7".
• Tires: Firesweep 8.00 x 14. Firedome, Fireflite 8.50 x 14. Adventurer 9.00 x 14.

POWERTRAIN OPTIONS:

• Automatic transmission was considered standard DeSoto equipment, but extra cost on Firesweep and Firedome models. There was no charge for automatic transmission in Fireflite and Adventurer models.
• Powerflite two-speed automatic transmission was available only in Firesweeps at $180 extra. Pushbutton gear shifting was standard
• Torqueflite three-speed automatic transmission was offered in all lines and was $220 extra in Firesweep and Firedomes. Pushbutton gear shifting was standard. Three-speed manual transmission with column mounted controls was a "deduct option."

SIGNIFICANT OPTIONS:

• Air conditioning w/group order ($404).
• Air Conditioning with Fresh Air heater ($493).
• Air Foam seat cushions - optional Firesweep, standard on Firedome, Fireflite, Adventurer ($11).
• Air rest on four-door and sport models ($27).
• Antenna, dual rear ($16).
• Backup lights - optional Firesweep, standard on Firedome, Fireflite, Adventurer ($12).
• Bendix-built electronic fuel-injection) system, Adventurer only ($637.20)
• Clock, self-winding, steering wheel clock ($30).
• Dual exhausts, except on Adventurer, ($34).
• Electric clock ($18).
• Engine - four-barrel power-pack, Firesweep only ($45).
• Front and rear carpets - optional Firesweep, standard on Firedome, Fireflite, Adventurer
• $14).
• Heater, Fresh Air ($89).
• Heater, Instant Air ($157).
• Non-Slip differential ($50).
• Outside mirror ($6).
• Padded safety panel (dash) - standard on Adventurer ($21).
• Power antenna, single ($24).
• Power brakes ($39).
• Power seat, six-way ($101).
• Power steering ($106).
• Power window lifts ($106).
• Radio, standard with antenna ($120).
• Radio, Electro Tune with antenna ($140).
• Rear seat speaker ($15).
• Rear window defogger ($21).
• Special paint finish, solid or two-tone ($71).
• Tinted glass ($32).
• Two-tone finish, standard type ($19).
• Undercoating ($14).
• Variable speed windshield wiper - standard on Firedome, Fireflite, Adventurer ($7).
• Wheel covers ($16).
• Whitewalls, standard on Adventurer ($42-45).
• Windshield washer ($12).

HISTORICAL BACKGROUND:  The Adventurer series was announced at the 1958 Chicago Auto Show, held on January 4 of 1958. All other Desoto models were introduced November 1, 1957.

PRODUCTION: DeSoto production took a huge nosedive for 1958 - a year in which the U.S. was the middle of a big recession and all automakers were suffering. Only 49,445 units produced, less than 28% of the previous year's total.  See attached chart for production numbers.