The official EPA figure for the 2024 BMW M340i xDrive Sedan is 26 MPG combined. To be clear, most people don’t buy this car primarily for its fuel economy. It’s a performance sedan first, and a relatively efficient machine second. The M340i appeals to drivers who crave a responsive, engaging driving experience with a touch of luxury, and they’re willing to accept mid-20s MPG in exchange for the grin-inducing power of its turbocharged inline-six.

City and highway performance

The M340i xDrive gets 23 MPG in the city and 31 MPG on the highway, according to the EPA. That city figure reflects stop-and-go traffic, where the engine’s power is less of a factor than the car’s weight and the efficiency of its automatic transmission. The highway figure illustrates the engine’s ability to cruise efficiently at higher speeds, aided by its well-spaced gear ratios and relatively low drag coefficient. Aggressive driving will significantly impact these numbers, especially in the city.

The car practically begs you to accelerate quickly, and doing so will send that 23 MPG figure plummeting.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 BMW M340i xDrive at $2,250. This figure is calculated based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway. The calculation also uses the national average fuel price, which means the actual cost will vary depending on where you live and how much you drive.

Because the M340i’s engine recommends premium fuel for optimal performance, expect to pay a bit more at the pump compared to vehicles that run on regular gasoline.

Real-world expectations

While the EPA figures provide a useful baseline, real-world fuel economy often differs. Drivers who frequently engage in spirited driving, long periods of idling, or mostly short trips may see figures closer to the low 20s overall. However, those who primarily drive on the highway at consistent speeds could potentially exceed the EPA’s 31 MPG rating. Understanding your own driving style and typical routes is critical for accurately predicting your fuel costs.

You can also view M340I MPG across all years to see what past drivers of this model have recorded.

How it compares

Compared to its competitors, the M340i’s fuel economy is competitive, but not class-leading. The Audi S4, with its 349-horsepower turbocharged V6, manages a similar 24 MPG combined. The Mercedes-AMG C43 sedan, a direct rival with 385 horsepower, gets around 22 MPG combined. Stepping outside the German brands, the Genesis G70 3.3T, offering a potent 365 horsepower, manages about 20 MPG combined.

The M340i’s edge comes from BMW’s expertise in balancing performance with efficiency, resulting in a car that delivers both thrills and reasonably economical fuel consumption. These buyers also see a slight increase in prestige owning a BMW.

You can review all Bmw fuel economy data on our site.

Tips to maximize efficiency

Use the M340i’s driving modes effectively. The “Eco Pro” mode optimizes engine and transmission settings for maximum fuel efficiency. While it does tame the engine’s responsiveness, it can make a noticeable difference on longer trips or in stop-and-go traffic.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, which forces the engine to work harder and consume more fuel. Check your tire pressure regularly and inflate them to the recommended levels specified on the doorjamb sticker.

Avoid aggressive acceleration and braking. Quick starts and hard braking waste fuel. Smooth, gradual acceleration and anticipating traffic conditions will help you conserve fuel and extend your driving range.

Reduce unnecessary weight. Carrying extra cargo in your trunk or back seat adds weight, which reduces fuel economy. Remove any items you don’t need for your daily commute or road trip.

Schedule regular maintenance. A well-maintained engine runs more efficiently. Follow the manufacturer’s recommended maintenance schedule for oil changes, air filter replacements, and other services to ensure optimal engine performance and fuel economy.