2023 BMW X4 M40i MPG & Specs — Real Fuel Cost
Quick answer
The 2023 BMW X4 M40i gets an EPA-estimated 21/26 MPG (city/highway) and 23 MPG combined, with an estimated $3,300/year fuel cost and 378 g/mi CO₂. Engine: 3 L 6-cyl.
The 2023 BMW X4 M40i with the 3-liter 6-cylinder premium gasoline engine returns an EPA-estimated 21 MPG in the city and 26 MPG on the highway, for a combined 23 MPG. This page summarizes the official EPA fuel-economy and emissions data for this configuration.
| Engine | 3 L 6-cyl |
| Transmission | Automatic (S8) |
| Drive | All-Wheel Drive |
| Fuel type | Premium Gasoline |
| Vehicle class | Small Sport Utility Vehicle 4WD |
| MPG — city | 21 |
| MPG — highway | 26 |
| MPG — combined | 23 |
| Annual fuel cost* | $3,300 |
| CO₂ tailpipe | 378 g/mi |
| EPA GHG score | 5/10 |
How efficient is it?
With a combined 23 MPG, the 2023 BMW X4 M40i sits in the moderate range for fuel economy. That is roughly 26% thirstier than the typical Small Sport Utility Vehicle 4WD of its era (31 MPG class average) — expect higher fuel bills than class-average alternatives.
Fuel economy and running costs
At about $3,300 per year in fuel (EPA estimate, 15,000 mi/yr), fuel is a major part of the cost of owning the 2023 BMW X4 M40i. Over five years that is roughly $16,500 at today's prices — before insurance, maintenance, and depreciation.
Emissions
The 2023 BMW X4 M40i emits approximately 378 grams of CO₂ per mile at the tailpipe, earning an EPA greenhouse-gas score of 5 out of 10. Lower emissions generally track higher fuel economy.
How to read these numbers
EPA figures come from standardized laboratory test cycles and are the same estimates shown on the vehicle's window sticker. Your real-world mileage depends on driving style, conditions, fuel grade, and maintenance. Use combined MPG and annual fuel cost to compare vehicles fairly.