Mazda 3 4-Door
30.3 MPG The 2018 Mazda 3 4-Door is EPA-rated at 30.3 MPG combined (27 city / 36.3 highway). Over 15,000 miles a year that is about 495 gallons, $1584 a year in fuel, or $0.106 per mile at $3.20/gal.
Across its full 2014–2018 run it averages 31.3 MPG, falling by 2 MPG over 5 model years.
Running cost at different fuel prices and mileages
The figure everyone actually wants, and the one the EPA does not publish — because it depends on a fuel price no agency will commit to.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.083 | $825 | $1238 | $1650 |
| $3.00/gal | $0.099 | $990 | $1485 | $1980 |
| $3.20/gal | $0.106 | $1056 | $1584 | $2112 |
| $3.50/gal | $0.116 | $1155 | $1733 | $2310 |
| $4.00/gal | $0.132 | $1320 | $1980 | $2640 |
| $4.50/gal | $0.149 | $1485 | $2228 | $2970 |
| $5.00/gal | $0.165 | $1650 | $2475 | $3300 |
Every model year
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2018 | 30.3 MPG | 27 | 36.3 | $2063 | 292 | 4 |
| 2017 | 30.6 MPG | 27 | 36.2 | $2040 | 291 | 5 |
| 2016 | 31.6 MPG | 28.2 | 38.2 | $1980 | 280 | 5 |
| 2015 | 31.6 MPG | 28.2 | 38.4 | $1980 | 280 | 5 |
| 2014 | 32.3 MPG | 28.8 | 38.5 | $1938 | 275 | 4 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
How it compares in its class
Among the 227 compact cars models tracked here, the Mazda 3 4-Door ranks 34 on current figures, against a class average of 26.6 MPG.
Closest more-efficient alternatives in the same class: Ford Focus FWD (30.4), BMW 330i Sedan (31), Kia Rio Eco (31), Mazda CX-3 2WD (31), Honda Civic 2Dr (32).
Tailpipe CO₂ is rated at 292 grams per mile, which works out to roughly 4.4 tonnes a year at 15,000 miles.
Questions
What MPG does the Mazda 3 4-Door get?
The 2018 Mazda 3 4-Door is rated at 30.3 MPG combined by the EPA — 27 city and 36.3 highway. Across all 5 model years in the database it averages 31.3 MPG, ranging from 29 to 33 depending on year and trim.
How much does a Mazda 3 4-Door cost in fuel per year?
At 30.3 MPG and 15,000 miles a year, it burns about 495 gallons — roughly $1584 a year with fuel at $3.20 a gallon, or $0.106 per mile. The EPA's own published annual figure for the 2018 model is $2063.
Has the Mazda 3 4-Door become more efficient over time?
No — it has actually gone backwards, from 32.3 MPG in 2014 to 30.3 in 2018. That usually reflects the model growing heavier, more powerful, or moving upmarket rather than the engineering getting worse.
Is the Mazda 3 4-Door efficient for its class?
It ranks 34 of 227 in the Compact Cars class on current figures, against a class average of 26.6 MPG. That is 3.7 better than typical for the class.
EPA test figures from fueleconomy.gov. Cost per mile and annual fuel spend are computed at a reference price of $3.20 per gallon — use your own price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.