Just recently, a leaked window sticker revealed that the 10-speed automatic-equipped 2018 Ford Mustang GT saw a slight gain in fuel economy. Now, Ford has officially revealed the fuel economy numbers for the whole Mustang lineup, and they match the leaked GT numbers of 16 mpg city, 25 mpg highway, and 19 mpg overall. That's not all, though. The official numbers also show that the standard turbocharged four-cylinder EcoBoost Mustangs get a small improvement, too.
The most efficient Mustang available is the automatic-equipped EcoBoost version. Its highway rating jumps 2 mpg to 32, and the overall rating improves by 1 mpg to 25. The manual version gets the same improvement to overall mpg of 25, but its highway number only increases by 1 mpg to 31. Both EcoBoost Mustangs have the same city economy rating of 21 mpg. Although these aren't huge gains, we're sure that Mustang buyers will be plenty satisfied, especially since the EcoBoost models aren't just slightly more fuel efficient, but they also make an extra 30 pound-feet of torque more than the previous iteration.
We reached out to Ford to double-check whether Performance Pack Mustangs will be EPA-rated differently than those without the package, and a representative informed us that although the V8-powered Mustang is unaffected by the package, Performance Pack EcoBoost Mustangs have lower fuel economy. The city fuel economy is lower than the normal car by 1 mpg, down to 20, and highway fuel economy is down by 3 mpg to 28 for the manual, and 29 for the automatic. Combined fuel economy for both transmission options is 23 mpg. Interestingly, the manual-transmission EcoBoost Mustang with Performance Pack has worse city and combined fuel economy by 1 mpg than the same Mustang last year.
Ford attributes these gains to improvements in aerodynamics, which include active grille shutters on Mustangs without the Performance Pack, a lower nose, and redesigned rocker panel guards that allow for smoother under-car airflow. Also, though we don't doubt these changes help, we do imagine there are other contributing factors to the increased fuel economy beyond aerodynamics. The reason being that the manual transmission-equipped V8 Mustang doesn't see any improvements over last year, despite sharing the same body as the automatic version.