23 MPG combined isn’t going to win any fuel efficiency awards, but for the 2021 BMW X3 M40i, it’s an acceptable compromise for the performance on offer. This isn’t a vehicle designed to conserve fuel; it’s a performance-oriented compact SUV built for drivers who prioritize driving enjoyment. The X3 M40i appeals to those who want a practical SUV with the heart of a sports car and understand that comes with certain tradeoffs. They accept this fuel economy as part of the price of admission to the M Performance club.

City and highway performance

The X3 M40i’s EPA ratings break down to 21 MPG in the city and 27 MPG on the highway. The city number reflects stop-and-go traffic, where the 3.0L turbocharged inline-six is constantly engaging and disengaging, burning more fuel. The highway figure is more promising, highlighting the engine’s ability to cruise efficiently once up to speed, thanks to the smooth-shifting 8-speed automatic transmission (S8). The difference between city and highway figures indicates that drivers who spend more time on the open road will see better overall fuel economy than those primarily navigating urban environments. This difference also suggests that using cruise control and maintaining a steady pace on the highway will significantly improve MPG.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2021 BMW X3 M40i at exactly $2,500. This figure is based on driving 15,000 miles per year and assumes fuel prices that represent a national average. Of course, actual fuel costs will vary depending on individual driving habits, local fuel prices, and the specific type of fuel used. While the $2,500 figure provides a useful point of comparison, it’s important for potential buyers to consider their own driving patterns and fuel expenses when estimating their personal fuel costs.

Real-world expectations

While the EPA estimates provide a standardized benchmark, real-world fuel economy can often differ. Drivers who frequently use the X3 M40i’s Sport or Sport+ modes, or who drive aggressively, should expect fuel economy to dip below the EPA estimates. However, those who adopt a more conservative driving style and prioritize efficiency can potentially achieve numbers closer to, or even slightly above, the EPA’s highway rating. Terrain also plays a role, as drivers in hilly or mountainous areas will likely experience lower MPG. The typical X3 M40i buyer understands that enjoying the car’s performance capabilities will impact fuel efficiency.

How it compares

The X3 M40i’s fuel economy slots it into a competitive segment, but its focus on performance differentiates it. The Acura RDX SH-AWD, another sporty compact SUV, achieves around 23 MPG combined, a close match, but lacks the outright power of the BMW. The Audi SQ5, a direct competitor, lands in similar territory with EPA ratings around 21 MPG combined, highlighting the inherent fuel demands of performance-oriented SUVs. Stepping outside the performance realm, the Lexus NX 300h hybrid boasts significantly better fuel economy, reaching around 31 MPG combined; however, it sacrifices the engaging driving experience that the X3 M40i offers. These comparisons illustrate that the X3 M40i’s targeted buyer is willing to accept slightly lower fuel economy for a car that delivers a far more exciting driving experience. You can find all Bmw fuel economy data on our site.

Tips to maximize efficiency

Avoid aggressive acceleration and braking. The X3 M40i’s turbocharged engine responds quickly to throttle inputs, but frequent hard acceleration will significantly reduce fuel economy. Smooth, gradual acceleration and anticipating traffic conditions to avoid sudden braking can help conserve fuel.

Maintain proper tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Regularly check and maintain the recommended tire pressure, which can be found on the driver’s side doorjamb or in the owner’s manual. This is especially crucial for a performance SUV like the X3 M40i, where tire pressure affects handling and performance as well as efficiency.

Use the ECO PRO mode. The X3 M40i features driving modes that can prioritize fuel efficiency. Selecting ECO PRO mode adjusts the engine, transmission, and climate control settings to optimize fuel consumption. While it may slightly reduce performance, it can make a noticeable difference on longer journeys.

Minimize idling. Letting the engine idle for extended periods wastes fuel. If you anticipate being stationary for more than a minute, consider turning off the engine. Modern engines are designed to restart quickly and efficiently, minimizing any potential wear and tear.

Keep up with scheduled maintenance. Regular maintenance, including oil changes and air filter replacements, ensures that the engine is running efficiently. A well-maintained engine consumes less fuel and operates more smoothly. Be sure to consult the X3 MPG across all years to see how maintenance might affect long-term efficiency.