Mercedes-Benz CLA-Class vs BMW 3 Series

The Mercedes-Benz CLA-Class is the more efficient of the two: it reaches 126 mpg combined versus 36 mpg for the BMW 3 Series, a 90 mpg advantage and costs about $1,600 less per year to fuel.

Across 5 measured categories, the Mercedes-Benz CLA-Class leads in 4. Figures are EPA test data, not manufacturer claims.

2015–2027

Mercedes-Benz CLA-Class

Compact Cars · 55 configurations

126mpg combined (best)
All Mercedes-Benz CLA-Class specs

2015–2026

BMW 3 Series

Compact Cars · 105 configurations

36mpg combined (best)
All BMW 3 Series specs

Head-to-head specifications

MetricMercedes-Benz CLA-ClassBMW 3 Series
Best combined MPG126 mpg36 mpg
Best city MPG127 mpg31 mpg
Best highway MPG124 mpg43 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$600$2,200
Lowest CO2 output273 g/mi158 g/mi
Engines offeredSIDI; Mild Hybrid, SIDI, SIDI; FFVSIDI & PFI; Mild Hybrid, SIDI, SIDI; PHEV, SIDI; Mild Hybrid
TransmissionsAutomatic (A2), Automatic (A1), Automatic (AM8)Automatic (S8), Manual 6-spd
DrivetrainsAll-Wheel Drive, Rear-Wheel Drive, Front-Wheel DriveRear-Wheel Drive, All-Wheel Drive
Fuel typesElectricity, Premium, Premium or E85Premium, Premium and Electricity, Diesel
EPA classCompact CarsCompact Cars
Years covered2015–20272015–2026
Configurations on record55105

Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.

CLA-Class vs 3 Series: common questions

Which is better on gas, the Mercedes-Benz CLA-Class or the BMW 3 Series?

The Mercedes-Benz CLA-Class is the more efficient of the two: it reaches 126 mpg combined versus 36 mpg for the BMW 3 Series, a 90 mpg advantage and costs about $1,600 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the Mercedes-Benz CLA-Class runs about $600 a year in fuel at its most efficient configuration, versus about $2,200 for the BMW 3 Series — a difference of roughly $1,600 per year.

What engines do the CLA-Class and 3 Series offer?

Mercedes-Benz CLA-Class: SIDI; Mild Hybrid, SIDI, SIDI; FFV. BMW 3 Series: SIDI & PFI; Mild Hybrid, SIDI, SIDI; PHEV, SIDI; Mild Hybrid.

Are they in the same vehicle class?

Yes — the EPA classifies both the Mercedes-Benz CLA-Class and the BMW 3 Series as Compact Cars, so they compete directly.

More CLA-Class comparisons

Comparison id: mercedes-benz-cla-class-vs-bmw-3-series