Improve Gas Mileage in Your 2021 BMW M3
Your 2021 BMW M3 hits 30 MPG on highways. You get this number in Efficient mode at steady 70 mph speeds. Real-world tests top the EPA's 23 MPG highway rating. The 15.6-gallon tank delivers 460 miles of range.
Choose the Best Drive Mode
Efficient mode calms the engine. It boosts MPG on long drives. Tests show 29.5 to 30.6 MPG on uphill highways at 70 mph. Reset your trip computer before trips to track gains. Pair it with Comfort chassis settings. This mix gives smooth rides and better fuel use.
Drive for Maximum Efficiency
Hold speeds constant at 70 mph on highways. Skip quick starts and hard brakes. These habits cut fuel use by 10-20% in the M3. Ease off the gas on hills. Live readouts show MPG drops instantly. Coast when safe. Pick routes with light traffic.
Stay on Top of Maintenance
Inflate tires to 35-38 PSI when cold. Low pressure cuts MPG by 5-10%. Check monthly. Use summer tires for grip and efficiency. Change oil every 5,000 miles with BMW-approved synthetic oil. Clean air filters improve airflow. New filters boost response and MPG.
Avoid Mods That Hurt MPG
Power mods like JB4 tunes on E35 fuel drop MPG to 18.1 on average. Stick to stock setup for top efficiency. Save mods for track days.
Track Your MPG Progress
Use these tips to see real gains:
| Tip | Expected MPG Gain | Notes |
|---|---|---|
| Efficient mode at 70 mph | Up to 30 MPG highway | Reset trip computer |
| Constant speed | 10-20% better | Avoid hard acceleration |
| Proper tire pressure | 5-10% better | Check monthly at 35-38 PSI |
Owners hit 460 miles per tank with these steps. You save $200-400 a year on gas at $3.50 per gallon.
Quick Action Steps
- Switch to Efficient mode on your next drive.
- Check tire pressure this weekend.
- Reset the trip computer before highways.
- Use Sidekick to track real MPG and find cheap gas nearby.