How many miles per gallon does a 1999 7.3 Powerstroke get?
Typically, a 1999 Ford Super Duty with the 7.3-liter Power Stroke diesel returns about 15–18 miles per gallon in mixed driving, with highway runs often in the 18–21 mpg range and city driving around 12–15 mpg depending on configuration and condition.
This article breaks down how those numbers come about, what factors push them up or down, and what you can realistically expect from common 1999 Power Stroke setups. The 7.3L Power Stroke powered many Ford F-Series trucks in 1999, and while modern diesels have improved efficiency, the 7.3 remains renowned for durability and straightforward maintenance.
Real-world MPG by Driving Condition
The following ranges reflect typical real‑world results reported by owners for common configurations (2WD/4x4, standard payload) on highways and city streets.
- City driving: 12–15 mpg
- Highway driving: 18–21 mpg
- Combined driving: 15–18 mpg
In practice, most drivers see mid‑teens in mixed use, with steady highway travel sometimes approaching the low 20s under favorable conditions and careful driving.
Key Factors That Shape Fuel Economy
Several variables can push mpg higher or lower on a 1999 Power Stroke diesel. Understanding them helps set realistic expectations.
- Drivetrain: Two-wheel drive vs. four-wheel drive configuration. 4x4 models typically use more fuel, especially in demanding or off-road conditions.
- Transmission: The 7.3L commonly paired with an automatic; manual gearings (less common in 1999) can yield different results depending on use.
- Cargo and payload: Heavier loads, towing, and bed weight reduce fuel economy.
- Maintenance state: A clean air filter, well-maintained fuel system, properly working injectors and turbo, and correct timing advance help sustain efficiency.
- Driving habits: Cruising speed, rapid acceleration, and idle time significantly affect mpg.
- Terrain and climate: Hills, headwinds, and altitude reduce efficiency versus flat, mild conditions.
- Tires and aerodynamics: Wider tires and poor aerodynamics increase rolling resistance and drag, lowering mpg.
Real-world improvements come from diligent maintenance and mindful driving. Small changes—like steady speeds on long highway trips and reducing idle time—can add up over a tankful.
Configurations in 1999: What to Expect by Setup
Different configurations in the 1999 Power Stroke lineup yield modest variations in fuel economy. The ranges below reflect common setups reported by owners.
- Two-wheel drive, light payload, automatic transmission: combined roughly 16–18 mpg; highway around 19–21 mpg; city around 13–15 mpg.
- Four-wheel drive or heavier payload, automatic: combined roughly 14–17 mpg; highway around 16–19 mpg; city around 12–14 mpg.
- Two-wheel drive, heavy towing or extreme payload: combined often in the mid-teens or lower; highway near 18–20 mpg on long, steady runs; city in the low teens.
These figures are approximate ranges and depend on the truck’s specific build, maintenance history, and how it’s driven.
Summary
The 1999 7.3 Power Stroke typically delivers mid‑teens in mixed driving, with highway mileage often flirting with the low‑20s under favorable conditions. Real‑world results are strongly influenced by drivetrain, payload, maintenance, and driving style. For anyone evaluating a vintage Power Stroke, tank‑to‑tank measurements and a well‑maintained intake and fuel system will provide the most reliable numbers.
