The Ford F-100, part of the broader F-Series lineup, occupied a crucial role in the American pickup truck market during the early 1970s. The sixth generation, produced from 1973 to 1974, saw the introduction of a more comfortable and feature-rich truck compared to its predecessors. The F-100 3.9 240 Six (115 hp) 4×4 Automatic represents an entry-level configuration within this generation, offering a balance between affordability, utility, and the capability of four-wheel drive. This variant was aimed at buyers needing a dependable work truck without the expense of larger engines or higher trim levels.
Technical Specifications
| Brand | Ford |
| Model | F-Series F-100/F-150 |
| Generation | F-Series F-100 VI Regular Cab |
| Type (Engine) | 3.9 240 Six (115 Hp) 4×4 Automatic |
| Start of production | 1973 |
| End of production | 1974 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 3 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Power | 115 Hp |
| Power per litre | 29.2 Hp/l |
| Engine displacement | 3933 cm3 / 240.01 cu. in. |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 101.6 mm / 4 in. |
| Piston Stroke | 81.03 mm / 3.19 in. |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Max. weight | 2540 kg / 5599.74 lbs. |
| Trunk (boot) space – minimum | 1713-1852 l / 60.49 – 65.4 cu. ft. |
| Length | 4803-5215 mm / 189.09 – 205.31 in. |
| Wheelbase | 2972-3378 mm / 117.01 – 132.99 in. |
| Wading depth | 630 mm / 24.8 in. |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels permanently, and the front wheels are driven through an electrically or mechanically operated clutch if necessary. |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 3 gears, automatic transmission Cruise-O-Matic |
| Front suspension | Independent coil spring |
| Rear suspension | Leaf spring |
| Front brakes | Disc |
| Rear brakes | Drum |
| Steering type | Worm-reduction unit |
| Power steering | Electric Steering |
| Tires size | 215/75 R15; 225/75 R15 |
| Wheel rims size | 7J x 15 |
Powertrain & Engine Architecture
The heart of the F-100 3.9 was Ford’s 3.9-liter (240 cubic inch) inline-six cylinder engine. Designated within Ford’s engine family as the 300 cubic inch family, this engine was known for its durability and relatively simple design. The 240 cubic inch version, however, was a shorter-stroke variant of the 300, resulting in slightly less power and torque. It utilized a single-barrel carburetor for fuel delivery, a common setup for the time, and featured a traditional pushrod valvetrain. The engine’s longitudinal front-engine layout was standard for Ford trucks of this era. Paired with this engine was the Ford Cruise-O-Matic three-speed automatic transmission. This transmission, while not known for its performance, provided smooth and relatively reliable shifting, making it a popular choice for drivers prioritizing ease of use over outright speed. The 4×4 system employed a transfer case allowing the driver to switch between two-wheel drive and four-wheel drive, enhancing the truck’s capability in challenging terrain.
Driving Characteristics
The 115 horsepower and approximately 190 lb-ft of torque produced by the 3.9-liter engine translated to adequate, but not exhilarating, performance. The automatic transmission, with its relatively wide gear ratios, prioritized fuel economy and smooth operation over rapid acceleration. Compared to the available V8 engines (302 and 390 cubic inches), the 3.9L six-cylinder was noticeably slower, particularly when hauling heavy loads or climbing steep hills. However, the lower engine weight contributed to better handling and a slightly more comfortable ride. The 4×4 system added weight and complexity, and the transfer case operation required driver input for engaging four-wheel drive. The overall driving experience was characterized by a focus on practicality and dependability rather than sporty performance.
Equipment & Trim Levels
The F-100 3.9 4×4 Automatic typically represented a base or near-base trim level. Standard features included a basic vinyl bench seat, a simple dashboard with essential gauges (speedometer, fuel level, temperature), and a manually operated heater. Power steering was often included, but air conditioning was typically an optional extra. The interior was utilitarian in design, prioritizing durability and ease of cleaning over luxury. Optional extras included upgraded radios, different wheel covers, and heavier-duty suspension components for increased payload capacity. The exterior typically featured minimal chrome trim and basic paint options.
Chassis & Braking
The F-100’s chassis was a traditional body-on-frame construction, providing a robust and durable platform. The front suspension utilized independent coil springs, offering a degree of ride comfort, while the rear suspension employed leaf springs, designed to handle heavier loads. Braking was accomplished via disc brakes on the front wheels and drum brakes on the rear. The braking system, while adequate for the truck’s weight and performance, lacked the stopping power of more modern systems. The 4×4 configuration added a solid front axle, contributing to the truck’s off-road capability but also potentially impacting ride quality on paved roads.
Market Reception & Comparison
The F-100 3.9 4×4 Automatic was generally viewed as a sensible and affordable option for buyers needing a capable work truck. Critics acknowledged its durability and dependability, but often noted its lack of power compared to V8-equipped models. Fuel economy, while not exceptional, was considered reasonable for a truck of its size and capability. Compared to the F-100 with the 302 cubic inch V8, the 3.9L six-cylinder offered lower initial cost and potentially better fuel economy, but at the expense of performance. The 3.9L automatic was a popular choice for those who prioritized ease of driving and didn’t require the extra power of a V8 for their typical tasks.
Legacy
The Ford F-100 3.9 4×4 Automatic, while not the most powerful or luxurious variant of its generation, has proven to be a surprisingly durable and reliable vehicle. The 3.9-liter inline-six engine is known for its longevity, and many examples are still on the road today. The simple design of the powertrain makes it relatively easy to maintain and repair. In the used car market, these trucks are often sought after by enthusiasts and collectors who appreciate their classic styling and rugged dependability. While not commanding the same prices as V8-powered or higher-trim models, the 3.9L 4×4 Automatic represents a solid and affordable entry point into the world of classic Ford trucks. Its enduring appeal lies in its ability to provide a simple, honest, and reliable transportation experience.
