DecodedCarsBMW 3 Series vs Mercedes-Benz CLA-Class
2026 BMW 3 Series vs 2026 Mercedes-Benz CLA-Class — two compact cars compared on efficiency, size, safety and reliability.
The short version
The BMW 3 Series is more fuel-efficient: 31 vs 30 MPG combined in its best version.
That works out to about $2,050 a year less in fuel for the Mercedes-Benz CLA-Class (EPA estimate, 15,000 miles).
Across all model years since 2005, the Mercedes-Benz CLA-Class has had fewer recall campaigns (0 vs 4).
The two cars
The 2026 BMW 3 Series is a compact car offered with 2 engines (2.0L 4-cyl turbo and 3.0L 6-cyl turbo), including a hybrid version and rear-wheel drive and all-wheel drive. It measures about 185 inches long and 72 inches wide on a 112-inch wheelbase, with a curb weight of roughly 3,494 lb (3-Series 330i Xdrive 4dr Sedan).
The 2026 Mercedes-Benz CLA-Class is a compact car offered with a 2.0L 4-cyl turbo engine, including a hybrid version and rear-wheel drive, all-wheel drive and front-wheel drive. It measures about 185 inches long and 72 inches wide on a 108-inch wheelbase, with a curb weight of roughly 4,597 lb (4dr Coupe).
Buying used? The 2024 3 Series and the 2024 CLA-Class have the fewest problems in our data.
Basics
Efficiency
Performance & space
Safety & reliability
Interest
Green = clearly better. Prices are not included. How we calculate this →
Which one should you choose?
Choose the BMW 3 Series if…
It doesn't clearly beat the Mercedes-Benz CLA-Class on any measure we track.
Choose the Mercedes-Benz CLA-Class if…
- You want an EV with more range (374 miles)
Pros & cons of each
2026 BMW 3 Series
- Hybrid version availableOffered as a hybrid as well as gas.
- AWD / 4WD available
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
2026 Mercedes-Benz CLA-Class
- Long EV rangeUp to 374 miles on a charge (EPA).
- Hybrid version availableOffered as a hybrid and electric as well as gas.
- AWD / 4WD available
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
Full 2026 BMW 3 Series specs →Full 2026 Mercedes-Benz CLA-Class specs →Compare fuel costs for your driving →Compare size & garage fit →