2021 head-to-head · Compact Car

2021 BMW 3 Series vs Mercedes-Benz CLA-Class

MPG, range and what each one really costs you to fuel, from official EPA ratings and recalculated with your own gas and electricity prices.

Swap sides
✓ Cheaper to run
$1,975/ year to fuel
30 MPG
✓ Cheaper to run
$2,043/ year to fuel
29 MPG

The 2021 BMW 3 Series is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $1,975 a year to fuel (30 MPG), versus $2,043 for the 2021 Mercedes-Benz CLA-Class (29 MPG). That's roughly $68 a year, or about $341 over five years.

Your numbers

Change these to match your driving and local prices. Every figure and chart on this page updates.

Fuel cost over 10 years

  • BMW 3 Series
  • Mercedes-Benz CLA-Class

Side by side

BMW 3 SeriesMercedes-Benz CLA-Class
$1,975 Your annual fuel cost $2,043
30 MPG Combined efficiency 29 MPG
26 MPG City 25 MPG
36 MPG Highway 35 MPG
94 cu ft Passenger volume 89 cu ft
13 cu ft Cargo volume 12 cu ft
298 g/mi Tailpipe CO₂ (g/mi) 306 g/mi
6/10 EPA fuel economy score 6/10
6/10 EPA greenhouse gas score 6/10
Gas Powertrain Gas
Premium gasoline Fuel Premium gasoline
2.0L 4-cyl turbo Engine / motor 2.0L 4-cyl turbo
8-speed automatic Transmission 7-speed dual-clutch
RWD Drivetrain FWD

✓ marks the better value. EPA scores run 1–10 (10 is best). Volumes come from the EPA interior volume index and aren't published for every body style.

BMW 3 Series vs Mercedes-Benz CLA-Class across model years

  • BMW 3 Series
  • Mercedes-Benz CLA-Class

Annual fuel cost of the most efficient configuration of each model year, at your prices. Click a point to open that year.

How they differ

Per EPA interior volume figures, the BMW 3 Series has more passenger space (94 vs. 89 cu ft); the BMW 3 Series has more cargo space (13 vs. 12 cu ft).

Among 37 2021 compact cars, the BMW 3 Series ranks 20th and the Mercedes-Benz CLA-Class 21st for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2021 BMW 3 Series or the 2021 Mercedes-Benz CLA-Class?

Measured by cost to drive, the BMW 3 Series. The BMW 3 Series is rated 30 MPG combined and the Mercedes-Benz CLA-Class 29 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2021 BMW 3 Series vs. the Mercedes-Benz CLA-Class per year?

At 15,000 miles a year with $3.95/gal premium gas, about $1,975 for the BMW 3 Series and $2,043 for the Mercedes-Benz CLA-Class.

Which has more cargo space?

The BMW 3 Series, with 13 cu ft of luggage volume versus 12 cu ft (EPA interior volume index).

BMW 3 Series vs Mercedes-Benz CLA-Class in other years

More 2021 comparisons

Or compare the 2021 BMW 3 Series with anything else:

Keep exploring