How much horsepower does a 1979 Mustang GT have?
The 1979 Mustang GT used a 5.0-liter V8 rated at about 140 horsepower (SAE net).
Context and the engine lineup for 1979
In 1979, Ford’s Mustang II era leaned toward lighter weight and emission-conscious engineering. The GT was the performance-oriented trim and relied on Ford’s 5.0-liter V8 (302 cu in) as its core powerplant. The official rating for this engine in the 1979 model year was around 140 horsepower in SAE net terms, with torque typically cited near 240 lb-ft. Ratings from brochures or flyers can vary slightly due to differences in testing standards or regional specifications, but 140 hp is the accepted figure for the GT in that year.
Beyond the GT, the Mustang II lineup offered smaller engines, including a 2.3-liter four-cylinder and a 3.3-liter inline-six, which produced notably less horsepower. Those non-GT engines illustrate how the model line balanced performance with fuel economy and regulatory constraints of the era.
Engine options and horsepower in 1979
Here is a summary of the core powerplants available around the 1979 model year and how horsepower generally stacked up. The GT specifically used the 5.0 L V8, which is where the 140 hp figure comes from.
- 5.0 L V8 (302 cu in) — approximately 140 hp (SAE net) in the 1979 Mustang GT.
- 2.3 L four-cylinder — typical output around 88–90 hp on the smaller-trim Mustangs of that era.
- 3.3 L inline-six — often in the 100–110 hp range, depending on emission controls and tuning.
In short, the Mustang GT’s power output in 1979 was dominated by the 302 V8’s roughly 140 hp, while other trims carried less powerful engines.
Why the numbers vary and what it means for collectors
Horsepower ratings from the late 1970s reflect SAE net standards, which measure power with accessories and components in place—leading to lower numbers than older gross ratings. When comparing vintage brochures or advertisements, it’s important to note the rating method used. For the 1979 Mustang GT, the canonical figure remains around 140 hp, with real-world performance influenced by transmission choice, exhaust setup, and overall vehicle weight.
Historical context and performance in daily use
During this period, even with roughly 140 horsepower, the Mustang GT offered a balanced driving experience for its class, emphasizing ride quality and handling alongside the engine’s take-off. Enthusiasts often point to the era’s distinct character—lighter weight, simpler exhaust tuning, and the era’s emissions controls—when discussing how that horsepower translated to real-world acceleration.
Summary
For a 1979 Mustang GT, the factory horsepower figure is about 140 hp from the 5.0 L (302 cu in) V8, measured using SAE net standards of the time. Other trims in the lineup used smaller engines with lower outputs, illustrating the era’s emphasis on fuel economy and emissions alongside performance. This horsepower figure remains the standard reference for collectors and restorers addressing 1979 Mustang GT models.
