Real-world highway MPG for the 2021 BMW M3
A 2021 BMW M3 delivers 29 to 32 MPG at steady 70 to 75 MPH on open highways. Owners often see 29 to 30 MPG on long, flat trips. This tops the EPA highway rating of 23 MPG. With a 15.6-gallon tank, you get 400 to 460 miles per fill-up in good conditions.
On calm, warm days with light traffic, the M3 hits 32 MPG during long freeway stretches. At 70 MPH, 30 MPG proves common. Speeds over 75 MPH, headwinds, or hills drop MPG to 22 to 27. Speed, wind, temperature, tires, and passing habits all affect results.
Typical highway results by speed
| Speed (MPH) | Typical MPG | Range per tank (15.6 gal) |
|---|---|---|
| 65 | 32 | 499 miles |
| 70 | 30 | 468 miles |
| 75 | 29 | 452 miles |
| 80 | 26 | 406 miles |
The M3 beats EPA numbers on road trips because the EPA test mixes city speeds and stops. Steady cruising in top gear eases engine load on the turbo inline-six.
Fuel costs add up quick. At $3.50 per gallon and 15,000 highway miles a year, 30 MPG runs $1,750. Drop to 24 MPG from faster speeds, and costs hit $2,190.
How to hit top MPG
- Set cruise control near 70 MPH on open roads.
- Inflate tires to door sticker pressure. Check monthly and before trips.
- Ease off hard passes and quick throttle. Gain speed early on hills.
- Ditch roof racks and extra weight when not needed.
- Keep windows up at speed. Run A/C only as needed.
- Fill with recommended octane. Stay current on maintenance.
Watch your M3's real-time MPG display. Note the best speeds and throttle for your car. Fuel up before the low light to skip detours.
Sidekick tracks your fill-ups and real MPG to spot patterns and cheap stations on routes.