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.
| A3 | GLB-Class | |
|---|---|---|
| Manufacturer | Audi | Mercedes-Benz |
| Starting price | — | — |
| Monthly payment | — | — |
| Fuel type | Gasoline | Hybrid |
| Fuel economy | 28.0 mpg | 27.0 mpg |
| CO₂ emissions | 323 g/mi | 311 g/mi–386 g/mi |
| Annual maintenance cost | — | — |
The 2019-2020 Audi A3 with the 2.0T engine commonly develops cracks in the plastic water pump and thermostat housing, causing coolant loss and overheating. Symptoms include a sweet coolant smell, puddles under the car, a low coolant warning, and a rising temperature gauge. If ignored, this can warp the cylinder head or damage the head gasket.
The 2021-2024 Audi A3 MIB 3 infotainment system can freeze, go black, or lose the rearview camera image due to software and hardware defects. Symptoms include a blank touchscreen, audio loss, constant Bluetooth disconnects, and a 'Camera System Unavailable' error. This can temporarily disable the required backup camera, creating a safety risk when reversing.
The optional panoramic sunroof on the 2021-2025 Audi A3 can develop frame flex, seal issues, and clogged drain tubes, leading to creaking, rattling, wind noise, and water intrusion. Symptoms include popping noises over bumps, damp headliners, and wet carpets near the A-pillars. If left unrepaired, water can reach electronic modules under the seats and cause electrical failures.
The 2021-2023 Audi A3 can suffer chronic 12V battery drain because the telematics or gateway module stays active after the car is locked. Symptoms include failure to start after 24-48 hours, low battery warnings, and the infotainment system resetting. This can leave the driver stranded and prematurely degrade the battery.
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.
Audi A3 and Mercedes-Benz GLB-Class suit different driving needs. The main differences below cover price, monthly payment, fuel economy, and running costs.
The models use different powertrains: A3 — Gasoline; GLB-Class — Hybrid. The better choice depends on your daily route and access to charging.
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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