29 MPG combined won’t win any hypermiling competitions, but it’s an impressive balance for the 2025 BMW M340i xDrive Sedan. This is a quick, all-weather sports sedan with a comfortable ride and a luxurious interior, not a stripped-down economy car. The M340i xDrive is engineered for performance; fuel economy is secondary, but not ignored.

City and highway performance

The EPA estimates 26 MPG in the city and 33 MPG on the highway. The city figure is respectable for a car with this much power, reflecting the efficiency technologies BMW has built into the powertrain. Highway performance is where the M340i xDrive excels. Its smooth eight-speed automatic transmission (S8) allows the engine to cruise at low RPMs on the open road. Also, the engine is designated as a 3.0l 4-cyl. Achieving over 30 MPG on long trips increases the car’s overall appeal. If you regularly travel and enjoy spirited driving, you can appreciate this highway MPG.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2025 BMW M340i xDrive Sedan will be $2,000. This assumes 15,000 miles of driving per year with fuel prices based on the national average. The real-world cost will vary depending on your driving habits, location, and fuel grade. Most drivers will recognize that using premium fuel helps the M340i xDrive to perform at its best, so the total fuel cost could easily be higher than $2,000.

Real-world expectations

The EPA provides a foundation for comparison, but real-world fuel economy depends heavily on driving style. If you spend most of your time in stop-and-go traffic and enjoy the M340i xDrive’s strong acceleration, expect numbers closer to the city estimate. However, if you drive mostly highway miles with a light foot, you should be able to meet or exceed the EPA’s highway figure. Owners who prioritize fuel efficiency can achieve close to the EPA combined number, while those who prioritize performance are likely to see a drop.

How it compares

The M340i xDrive occupies a sweet spot in the performance sedan segment. The Audi S4, with its turbocharged 3.0-liter V6 and standard Quattro all-wheel drive, achieves around 24 MPG combined. The Mercedes-AMG C43 Sedan, offering similar performance, lands in the same ballpark. The Acura TLX Type S is rated for 21 MPG combined. The M340i xDrive’s slightly better fuel economy, compared to others in its class, is a deciding factor for some buyers. For shoppers who are interested in M340I MPG across all years there is even more data available.

Tips to maximize efficiency

Avoid aggressive acceleration and braking. The M340i xDrive is capable of explosive performance, but using this regularly will dramatically reduce fuel economy. Focus on smooth, gradual inputs, anticipating traffic flow to minimize unnecessary stops and starts.

Maintain proper tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Check your tire pressure regularly and inflate them to the recommended levels, found on the driver’s side doorjamb.

Use cruise control on the highway. Engaging cruise control helps maintain a consistent speed, reducing fluctuations in throttle input and improving fuel efficiency. This is effective on long, flat stretches of road.

Reduce unnecessary weight. Carrying extra weight in the car decreases fuel economy. Remove any items you don’t need, especially heavy objects in the trunk. By reducing the amount of weight, you reduce the amount of energy needed to move your car.

Consider using ECO PRO mode. The M340i xDrive typically has different drive modes to select. These modes recalibrate the engine and transmission settings for optimum fuel efficiency. ECO PRO mode can noticeably improve fuel economy, especially in city driving. Visit all Bmw fuel economy data.