Compare two new cars by price, estimated monthly payment, fuel economy, and other specifications. Data comes from the CarPayCheck.com catalog and uses your selected financing terms.
| 4 Series | GLB-Class | |
|---|---|---|
| Manufacturer | BMW | Mercedes-Benz |
| Starting price | — | — |
| Monthly payment | — | — |
| Fuel type | Hybrid | Hybrid |
| Fuel economy | 29.0 mpg | 27.0 mpg |
| CO₂ emissions | 285 g/mi–320 g/mi | 311 g/mi–386 g/mi |
| Annual maintenance cost | — | — |
The most frequently reported issue is electrical system malfunctions, with complaints logged for model years 2019, 2020, 2021, 2022, and 2025. The source does not itemize symptoms, but the category indicates faults in electrical components. Fire-related severity signals were also recorded for several years, making electrical problems a safety-relevant area to inspect.
Powertrain and engine complaints were reported for model years 2019, 2020, 2021, and 2022, with 12 complaints in 2019 and 10 in 2020. The source does not specify symptoms, but the category covers engine and transmission faults. It is recommended to have a specialist inspect for drivability problems, warning lights, fluid leaks, and repair history.
Service brake complaints were logged for model years 2023 and 2024, with 7 complaints in 2023 and 4 in 2024, plus hydraulic brake complaints in 2023. The source does not detail symptoms, but the category indicates brake system faults. Inspecting brake pedal feel, fluid level, lines, and warning messages is advised.
Yes, 2020-2021 GLB models are covered by NHTSA recall 21V-990 for corrosion of the front axle integral carrier, and rerev.com lists it as the top failure for those years. Symptoms include structural weakening of the front axle mounting points, which can lead to loss of steering control, component detachment, or increased crash risk. Before buying, check the VIN through the NHTSA recall checker and inspect the front axle carrier for corrosion or evidence of replacement. No specific repair cost is documented in the research, but it is considered a high-cost structural repair.
The 2021 GLB-Class is specifically flagged for sunroof failure, with CarComplaints ranking that model year worst for repair cost. Symptoms include the sunroof failing to open or close, water leaks into the cabin, or glass and mechanism breakage, which can lead to interior water damage, electrical short circuits, and potential safety hazards. No precise repair cost is given in the research, so only a high-cost estimate is implied.
BMW 4 Series and Mercedes-Benz GLB-Class suit different driving needs. The main differences below cover price, monthly payment, fuel economy, and running costs.
Both models use Hybrid. Fuel economy is 4 Series — 29.0 mpg; GLB-Class — 27.0 mpg. 4 Series uses less energy in everyday driving.
The final choice is about more than numbers: annual distance, city or highway use, and the space your household needs all matter. Use the CarPayCheck.com calculator to apply your financing terms and evaluate both cars in your situation.
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