While a combined 26 MPG won’t earn the 2024 BMW M340i any fuel efficiency awards, it’s a reasonable figure for a performance sedan packing a turbocharged inline-six that delivers over 380 horsepower. This car appeals to enthusiasts who appreciate a finely balanced machine for both spirited driving and highway cruising. These drivers accept decent fuel economy in exchange for the M340i’s exhilarating driving experience.

City and highway performance

The EPA estimates the M340i will achieve 23 MPG in the city and 31 MPG on the highway. This difference shows the engine’s efficiency when cruising at steady speeds. The turbocharged engine can be sensitive to aggressive throttle inputs, which will likely happen often given the car’s performance. The eight-speed automatic transmission, expertly tuned to keep the engine in its sweet spot, helps achieve these numbers.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 BMW M340i at $2,250. This is based on driving 15,000 miles per year and using national average fuel prices for premium unleaded gasoline, the recommended fuel for optimal performance. This is an EPA estimate, and actual fuel costs may vary depending on driving habits, local fuel prices, and city versus highway driving.

Real-world expectations

While the EPA estimates provide a useful baseline, real-world M340i MPG will vary. Drivers who frequently exploit the car’s performance may see figures closer to the city rating, or even lower. However, those who spend a lot of time on the highway, driving conservatively, could exceed the 31 MPG highway rating. Expect an average of around 24-28 MPG in combined driving, with a heavier foot resulting in the lower end of that range.

How it compares

The M340i’s fuel economy is competitive for its class. The Audi S4, with its turbocharged V6, achieves a similar 24 MPG combined. The Mercedes-AMG C43 also gets around the mid-20s. The Acura TLX Type S falls slightly behind with a combined rating of 21 MPG. Buyers in this segment often cross-shop performance and luxury and while fuel economy is a consideration, it’s rarely the primary deciding factor. Instead, it’s part of a broader equation that balances power, handling, and overall driving experience.

Tips to maximize efficiency

The M340i’s driving mode settings can affect fuel consumption. Selecting “Eco Pro” mode will remap the throttle response and shift points to prioritize efficiency, making the car feel less responsive but improving MPG. Using this mode during long highway drives can save you money.

While tempting to launch hard from every stoplight, smooth and progressive acceleration saves fuel. Avoid aggressive throttle inputs whenever possible, allowing the engine to gradually build power. Anticipate traffic flow to minimize unnecessary braking and acceleration. The M340i’s brakes are exceptional, but every stop represents wasted kinetic energy.

Ensure that your tires are properly inflated since underinflated tires increase rolling resistance, which reduces fuel economy. Regularly check your tire pressures and maintain them at the recommended levels found on a sticker in the driver’s side doorjamb. This simple step is often overlooked but can make a real difference.

Avoid carrying unnecessary weight as extra cargo adds to the car’s overall weight, requiring the engine to work harder and consume more fuel. Remove any non-essential items from the trunk or backseat. Every little bit helps. Consider exploring M340I MPG across all years to see how different generations compare.

Regular maintenance is critical for optimal fuel economy. Ensure that your engine air filter is clean, and that your car receives regular oil changes. A well-maintained engine runs more efficiently, improving MPG. Don’t neglect routine maintenance to ensure peak performance. For all BMW fuel economy data, browse our guide.