The 2021 BMW 3 Series delivers an EPA-certified 25–30 MPG combined across 6 configurations. Hybrid variants achieve up to 26 MPG combined, compared to 30 MPG for standard gasoline trims. Estimated annual fuel costs range from $2,550 to $3,050.
Factual efficiency differences across gasoline, hybrid, plug-in hybrid, and electric variants
Annual Fuel Cost: $2,550–$2,700.
Annual Fuel Cost: $2,900–$3,050 (saves vs gas).
Gasoline Combined: 28 MPG • Annual Cost: $2,700.
Laboratory certification test values across engine, transmission, and drivetrain permutations
| Configuration / Model | Powertrain | Drivetrain | Transmission | City | Highway | Combined | EV Range | Annual Fuel Cost | CO2 (g/mi) |
|---|---|---|---|---|---|---|---|---|---|
| 330i Premium | 2L 4-Cyl Gas | Rear-Wheel Drive | Automatic (S8) | 26 MPG | 36 MPG | 30 MPG | — | $2,550 | — |
| 330i xDrive Premium | 2L 4-Cyl Gas | All-Wheel Drive | Automatic (S8) | 25 MPG | 34 MPG | 28 MPG | — | $2,700 | — |
| 330e Premium and Electricity | 2L Plug-in Hybrid | Rear-Wheel Drive | Automatic (S8) | 72 MPGe (25 MPG) | 80 MPGe (33 MPG) | 75 MPGe (28 MPG) | 23 mi | $2,700 | — |
| M340i Premium | 3L Hybrid | Rear-Wheel Drive | Automatic (S8) | 23 MPG | 32 MPG | 26 MPG | — | $2,900 | — |
| M340i xDrive Premium | 3L Hybrid | All-Wheel Drive | Automatic (S8) | 22 MPG | 31 MPG | 25 MPG | — | $3,050 | — |
| 330e xDrive Premium and Electricity | 2L Plug-in Hybrid | All-Wheel Drive | Automatic (S8) | 64 MPGe (22 MPG) | 71 MPGe (30 MPG) | 67 MPGe (25 MPG) | 20 mi | $3,050 | — |
Standardized annual energy consumption and operating cost metrics based on 15,000 annual miles
Based on $3.50 per gallon regular gasoline
Estimated annual energy units needed for 15,000 miles
Compared to the average new vehicle over 5 years
Cross-reference safety ratings, owner defect complaints, and recall campaigns
Vehicle summary, specifications, and primary KPI metrics.
NHTSA 5-Star NCAP crash tests, rollover risk, and active driver assistance.
NHTSA consumer defect complaint filings by affected component.
Official safety recall notices, defects, and free repair instructions.
Direct, deterministic answers synthesized from verified United States government databases for the 2021 BMW 3 Series
The 2021 BMW 3 Series achieves an EPA-certified rating of 25 to 30 MPG combined across 6 certified configuration(s).
City ratings range from 22 to 30 MPG, and highway ratings range from 25 to 36 MPG.
Hybrid (HEV) models achieve up to 26 MPG combined, delivering approximately -4 more miles per gallon than standard gasoline configurations (up to 30 MPG combined).
Gas-electric hybrid variants use regenerative braking and electric assist motors to reduce fuel consumption in stop-and-go city driving.
Using AutoUtility's standardized operating cost model, estimated annual fueling and energy costs range between $2,550 and $3,050 for the 2021 BMW 3 Series.
Calculated under AutoUtility's standardized methodology (15,000 miles per year, 55% city / 45% highway driving, $3.50/gallon regular gasoline, $0.16/kWh electricity) using official EPA dynamometer consumption ratings.
Fuel economy ratings, electric range figures, and energy cost estimates on this page are retrieved directly from the United States Environmental Protection Agency (EPA) and U.S. Department of Energy (FuelEconomy.gov) certified vehicle database under 40 CFR Part 600.
Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.