16 MPG combined. Those are the numbers to consider if you’re thinking about a 2015 BMW M6 Convertible powered by its howling 4.4L V8. This isn’t a car you choose for its efficiency, of course. It’s a statement, a visceral experience draped in leather and carbon fiber designed to deliver breathtaking performance. Buyers who write the check for an M6 Convertible know exactly what they’re getting into. Fuel economy is a distant concern, practicality almost irrelevant. This is about the thrill of the open road, the sound of the exhaust, and the feeling of power under your right foot.

City and highway performance

The EPA estimates 14 MPG in the city and 20 MPG on the highway. The difference between these two figures shows the M6’s thirst in stop-and-go traffic. Its power is best used on open stretches of asphalt, where the engine can operate more efficiently at cruising speeds. However, even on the highway, heavy use of the M6’s power will bring that 20 MPG figure down. The seven-speed automated manual gearbox (AM-S7) helps with efficiency when driven with some restraint.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2015 BMW M6 Convertible at $3,600. This figure is based on driving 15,000 miles per year, using fuel prices based on national averages at the time of calculation (which will vary over time based on fluctuations in the petroleum market). This is a reminder of the price you pay for this level of performance and luxury. Drivers who frequently use the M6’s performance will likely see an annual fuel cost exceeding this estimate.

Real-world expectations

Forget the EPA numbers if you plan on regularly enjoying the M6 Convertible. Aggressive acceleration, frequent shifting, and the urge to hear the engine will drop fuel economy below the official estimates. Expect to see numbers closer to the city rating, even on mixed driving. The M6’s fuel tank is reasonably sized, but frequent fill-ups are an unavoidable reality. Be realistic about your driving habits and expectations.

If you want fuel efficiency, there are many other vehicles to consider. However, if the sound of a high-performance V8 convertible are your primary desires, the added cost of fuel might be worth paying.

How it compares

Compared to its rivals, the M6 Convertible’s fuel economy is normal for this segment. The Mercedes-AMG SL63, with its potent twin-turbo V8, typically returns numbers in the same ballpark. A Porsche 911 Turbo Cabriolet, for example, gets better fuel economy, closer to 19 MPG combined, but attracts a different type of buyer who values precision handling. The Audi R8 Spyder, although naturally aspirated, lands somewhere in-between. For those cross-shopping, remember to browse all Bmw fuel economy data to understand where the M6 and its variants rank within the automaker’s lineup. Those interested in other models within the range can also learn more about M6 MPG across all years.

Tips to maximize efficiency

Use the M6’s driving modes. Comfort mode might reduce the throttle response and shift points, but it helps to even out the fuel consumption. Selecting Efficient mode can also alter throttle mapping and gear changes to optimize MPG in daily driving. Save Sport and Sport+ modes for when you want to use the car’s full potential, understanding they will increase fuel consumption.

Minimize idling. The M6’s large displacement engine consumes fuel even when stationary. Turn off the engine if you anticipate being stopped for more than a minute or two. This can make a difference, especially during city driving. Small efforts matter.

Maintain proper tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Check your tire pressures and inflate them to the recommended levels, which are typically found on a sticker inside the driver’s side door jamb or in the owner’s manual. A simple tire pressure check can improve fuel economy.

Avoid aggressive acceleration and braking. The M6 can accelerate quickly, but every hard launch and abrupt stop uses fuel. Smooth driving is key to maximizing efficiency. Anticipate traffic flow, maintain a safe following distance, and accelerate and decelerate gradually. This disciplined approach saves fuel and adds quietness to the ride.