BMW 328ci Convertible
20.5 MPG The 2012 BMW 328ci Convertible is EPA-rated at 20.5 MPG combined (17.5 city / 26 highway). Over 15,000 miles a year that is about 732 gallons, $2341 a year in fuel, or $0.156 per mile at $3.20/gal.
Across its full 2007–2012 run it averages 20.6 MPG, essentially flat across 6 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 | $0.122 | $1220 | $1829 | $2439 |
| $3.00/gal | $0.146 | $1463 | $2195 | $2927 |
| $3.20/gal | $0.156 | $1561 | $2341 | $3122 |
| $3.50/gal | $0.171 | $1707 | $2561 | $3415 |
| $4.00/gal | $0.195 | $1951 | $2927 | $3902 |
| $4.50/gal | $0.220 | $2195 | $3293 | $4390 |
| $5.00/gal | $0.244 | $2439 | $3659 | $4878 |
Every model year
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2012 | 20.5 MPG | 17.5 | 26 | $3750 | 434 | 2 |
| 2011 | 20.5 MPG | 17.5 | 26 | $3750 | 434 | 2 |
| 2010 | 20.5 MPG | 17.5 | 26.5 | $3750 | 434 | 2 |
| 2009 | 20.5 MPG | 17.5 | 27 | $3750 | 434 | 2 |
| 2008 | 20.5 MPG | 17.5 | 27 | $3750 | 434 | 2 |
| 2007 | 21 MPG | 17.5 | 27 | $3650 | 423 | 2 |
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 229 subcompact cars models tracked here, the BMW 328ci Convertible ranks 152 on current figures, against a class average of 24.2 MPG.
Closest more-efficient alternatives in the same class: Hyundai Tiburon (20.8), Subaru XT 4WD (20.8), BMW 135i Convertible (21), Chrysler LeBaron Convertible (21), Ford Mustang (21).
Tailpipe CO₂ is rated at 434 grams per mile, which works out to roughly 6.5 tonnes a year at 15,000 miles.
Questions
What MPG does the BMW 328ci Convertible get?
The 2012 BMW 328ci Convertible is rated at 20.5 MPG combined by the EPA — 17.5 city and 26 highway. Across all 6 model years in the database it averages 20.6 MPG, ranging from 20 to 21 depending on year and trim.
How much does a BMW 328ci Convertible cost in fuel per year?
At 20.5 MPG and 15,000 miles a year, it burns about 732 gallons — roughly $2341 a year with fuel at $3.20 a gallon, or $0.156 per mile. The EPA's own published annual figure for the 2012 model is $3750.
Has the BMW 328ci Convertible become more efficient over time?
Barely. It sits at 20.5 MPG today against 21 in 2007 — essentially flat across 6 model years, with efficiency gains offset by weight and power creep.
Is the BMW 328ci Convertible efficient for its class?
It ranks 152 of 229 in the Subcompact Cars class on current figures, against a class average of 24.2 MPG. That is 3.7 worse 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.