17 MPG combined is what you can expect when owning a 2025 BMW M8 Competition Convertible, a thrilling and exclusive machine that delivers performance and open-air thrills. This isn’t a car built for saving gas; it’s a statement, a visceral experience, and a rolling sculpture powered by a snarling V8. For those who prioritize driving pleasure over saving money at the pump, the fuel economy is simply one factor to consider.

City and highway performance

The M8 Competition Convertible’s EPA ratings are 15 MPG in the city and 22 MPG on the highway. The city figure reflects the stop-and-go nature of urban environments, forcing the potent 4.4L twin-turbo V8 to work harder, especially with its strong low-end torque. The highway figure is more palatable, but it’s easy to dip far below that number when exploiting the engine’s capabilities during spirited cruising. The eight-speed automatic transmission (S8), while incredibly smooth and responsive, also contributes to fuel consumption. Modern automatics are more efficient than older ones, but managing 617 horsepower can still impact efficiency.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2025 BMW M8 Competition Convertible to be $3,400. This calculation is based on driving 15,000 miles per year and uses the national average fuel price for premium gasoline, which is required for optimal performance. Your actual fuel costs will vary depending on your driving habits, local fuel prices, and how often you enjoy the car’s performance. If you drive more aggressively or live in an area with higher gas prices, expect to exceed this figure. The estimated annual fuel cost is an important component of evaluating the total cost of ownership, so budgeting extra funds to absorb any variance in the estimate is wise.

Real-world expectations

If you plan to fully exploit the M8 Competition Convertible’s performance, forget the EPA numbers. Owners who frequently engage Launch Control, explore the upper reaches of the tachometer, or enjoy the intoxicating surge of acceleration will likely see fuel economy figures well below the official ratings. Drivers who adopt a more relaxed driving style and primarily use the car for longer highway journeys might get closer to the EPA estimates, but even then, achieving the rated MPG requires conscious effort.

How it compares

The fuel economy of the M8 Competition Convertible is typical of high-performance luxury vehicles. Consider the Porsche 911 Turbo Cabriolet, a direct competitor in terms of performance and price, which gets around 17 MPG combined. The Mercedes-AMG SL63, another contender, achieves a similar 16 MPG combined. More fuel-efficient luxury convertibles are available, such as the Lexus LC 500 Convertible with its 19 MPG combined, but these vehicles prioritize a different balance of performance, luxury, and efficiency. The M8 buyer is typically less concerned with squeezing every last mile out of a gallon and more focused on the driving experience offered by a high-output V8. Comparing M8 MPG across all years can also show how the current model stacks up against previous versions.

Tips to maximize efficiency

The M8 Competition Convertible isn’t designed for fuel sipping, but a few strategies can help you maximize your MPG without sacrificing too much driving enjoyment. Avoid aggressive acceleration and hard braking. The car’s power makes feathering the throttle easy, gentle inputs yield surprising results. Sudden stops are also detrimental, so anticipate traffic flow and cruise to maintain the best efficiency.

Use the M8’s driving modes. Selecting “Comfort” or “Eco Pro” softens throttle response and optimizes the transmission for efficiency. While these modes tame the beast somewhat, they can still provide ample performance for everyday driving while conserving fuel.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, negatively impacting fuel economy. Regularly check your tire pressure and maintain it at the recommended levels to optimize efficiency and tire life.

Minimize idling. Modern engines are designed to run efficiently when moving. Excessive idling, especially with the air conditioning running, wastes fuel. If you’re stopped for more than a minute or two, consider turning off the engine.

Consider modifying your routes. Avoiding stop-and-go traffic and choosing routes with fewer hills will keep the engine at a more consistent speed and increase the car’s average fuel consumption. This is especially true if the vehicle is more often driven in the city versus on the highway. Comparing all Bmw fuel economy data can show typical MPG ratings for this vehicle type.