The 2023 BMW M340i isn’t bought for its 26 MPG combined fuel economy. This sports sedan is built for exhilarating performance and precise handling, efficiency is secondary, but welcome. M340i buyers want a thrilling driving experience and accept the fuel consumption.

City and highway performance

The M340i’s EPA ratings are 23 MPG in the city and 31 MPG on the highway. The city figure reflects urban driving, where the turbocharged engine spools up and down. 23 MPG is respectable for a 382-horsepower car, but easily influenced by a heavy foot. The highway figure of 31 MPG is attainable with relaxed cruising. The smooth-shifting 8-speed automatic transmission helps keep the engine efficient at higher speeds. Use adaptive cruise control to achieve or exceed this rating on long journeys.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2023 BMW M340i at $2,250. This is based on 15,000 miles per year and national average fuel prices. Actual fuel costs vary depending on driving habits, local fuel prices, and fuel type. The M340i doesn’t require premium fuel, but it’s recommended for optimal performance, which increases ownership costs.

Real-world expectations

Real-world fuel economy differs from the EPA estimate. Aggressive driving, short trips, and weather impact fuel consumption. Drivers who accelerate smoothly, anticipate traffic, and maintain a steady highway speed often achieve figures close to the EPA estimates, or even slightly better.

Some owners report averaging around 28 MPG in mixed driving, showing the M340i can be efficient when driven carefully.

How it compares

The M340i is in a competitive segment. The Audi S4, with its standard quattro all-wheel-drive, achieves an EPA-rated 24 MPG combined. The Mercedes-AMG C43 Sedan nets 22 MPG combined. The Genesis G70 3.3T, with similar performance and luxury, manages 20 MPG combined. The M340i isn’t the efficiency leader, but it balances performance and fuel economy. Buyers often sacrifice a few MPG for the M340i’s superior handling and engaging driving. See M340I MPG across all years for a broader historical perspective.

Tips to maximize efficiency

Use the M340i’s driving modes. “Eco Pro” mode optimizes engine and transmission settings for maximum fuel efficiency. While it may slightly reduce throttle response, it can affect fuel consumption in city driving.

Monitor your tire pressure. Underinflated tires increase rolling resistance, decreasing fuel economy. Maintaining the correct tire pressure, as indicated on the doorjamb sticker, can improve MPG and extend tire life. Tire pressure changes with temperature, so check regularly.

Avoid unnecessary idling. If you’re stopped for more than a minute, turn off the engine. Modern cars restart quickly, and idling wastes fuel. This is true with turbocharged engines, which burn more fuel at idle than naturally aspirated engines.

Use cruise control judiciously. On flat highways, cruise control maintains a consistent speed, reducing fuel consumption. On hilly terrain, cruise control downshifts to maintain speed uphill, which is less efficient. See what works best for your driving. If you’re curious about other models in this vehicle’s family, see all Bmw fuel economy data.