23 MPG combined isn’t going to win any awards for fuel sipping, but in the context of the 2018 Ford Mustang Convertible 2.3L 4-cylinder, it’s an acceptable compromise. This isn’t a Prius; it’s a drop-top muscle car (albeit with a smaller engine) designed to deliver open-air thrills, head-turning style, and a connection to a legendary nameplate. The typical buyer isn’t prioritizing ultimate fuel efficiency above all else; they’re buying an experience. They want the wind in their hair, the rumble of an exhaust (even a four-cylinder one), and the iconic silhouette of a Mustang. The fuel cost is a secondary, though certainly considered, factor.

City and highway performance

The EPA estimates peg the 2018 Mustang Convertible 2.3L at 20 MPG in the city and 29 MPG on the highway. That city figure reflects the reality of stop-and-go traffic, where the engine spends more time idling or accelerating from a standstill. The automatic transmission, however, is programmed to shift quickly and keep the engine in its most efficient range, mitigating some of the fuel penalty. The highway number is where the 2.3L EcoBoost shines. It cruises comfortably and efficiently, aided by the 10-speed automatic transmission (S10) which finds the optimal gear for sustained speeds. This is where drivers will see the best return on their fuel investment, making it a respectable choice for longer journeys.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2018 Ford Mustang Convertible 2.3L (with automatic transmission) to be precisely $1,900. This figure is based on driving 15,000 miles per year, using a blend of city and highway driving, and factoring in the national average fuel prices at the time of the estimate. It’s important to remember that this is just an estimate; your actual fuel costs will vary depending on your driving habits, the type of fuel you use, and the prevailing fuel prices in your area. However, it provides a useful benchmark when comparing it to other vehicles.

Real-world expectations

While the EPA estimates offer a standardized comparison point, real-world fuel economy can fluctuate. Aggressive driving, frequent use of the air conditioning, and less-than-ideal road conditions can all negatively impact your MPG. If you have a heavy foot and enjoy exploiting the Mustang’s performance capabilities, expect to see numbers closer to the low end of the estimate, perhaps even dipping below 20 MPG for city driving. On the other hand, if you adopt a more relaxed driving style, anticipate potentially exceeding the highway estimate, especially on long, flat stretches of road. Regular maintenance, like ensuring proper tire inflation and replacing air filters, also plays a role in optimizing fuel efficiency.

How it compares

Compared to its rivals, the Mustang Convertible 2.3L falls somewhere in the middle of the pack. The Mazda MX-5 Miata, for example, sips fuel with an EPA rating of 29 MPG combined with the automatic transmission. But, the Miata trades rear seats for a smaller, more agile package. A comparable Chevrolet Camaro Convertible with the base 2.0L turbo engine achieves around 25 MPG combined, slightly better than the Mustang; however, the Camaro offers a different aesthetic and driving experience. If you explore MUSTANG MPG across all years you’ll find that this model is relatively efficient compared to V8 models. Ultimately, the decision hinges on priorities. If fuel economy is important, the Miata is the clear winner. But if you need the Mustang’s blend of style, performance, and heritage, the marginal difference in MPG may be a worthwhile price to pay.

Tips to maximize efficiency

Take advantage of the Mustang’s drive modes. The “Normal” or “Eco” mode will optimize the engine and transmission settings for fuel efficiency, while sacrificing some throttle response. Avoid using “Sport” mode unless you’re truly looking for maximum performance.

Gentle acceleration and braking are key to saving fuel. Avoid jackrabbit starts and hard braking, as these consume considerably more fuel and wear down components faster. Anticipate traffic flow and maintain a steady speed whenever possible.

Ensure your tires are properly inflated to the recommended pressure listed on the door jamb sticker. Underinflated tires increase rolling resistance, which negatively impacts fuel economy. Check your tire pressure regularly, especially during temperature changes.

Reduce unnecessary weight in the vehicle. Extra cargo in the trunk or back seat adds weight and forces the engine to work harder, reducing fuel efficiency. Empty the trunk of any non-essential items.

Limit your idling time. If you anticipate being stopped for more than a minute, turn off the engine. Modern engines are designed to start quickly and efficiently, and restarting the engine consumes less fuel than idling for extended periods. You can find all Ford fuel economy data here.