2019 — 2026
2.0L M139 I4 Turbo - Flagship 'S' Performance Version
Petrol
While driving on a quiet road, engage Sport+ mode and perform a firm acceleration from low speed. | Observation: Listen for any hesitation or 'stutter' in the 8-speed DCT gearbox, as smooth, snappy shifts are the hallmark of this transmission.
Check this by turning the steering wheel to full lock in both directions while at a standstill. | Observation: Be mindful of any 'scrubbing' or clicking noises, which could indicate the complex 4MATIC+ drivetrain or steering rack components need a closer inspection.
During your inspection, physically inspect the inner sidewalls of the front tires. | Observation: The aggressive camber settings on the A45 S can lead to inner edge wear; checking this ensures you aren't immediately looking at a full set of performance rubber.
After the drive, leave the engine running and check the exhaust note for consistency. | Observation: Ensure the valved exhaust system toggles between 'Quiet' and 'Powerful' modes correctly, as the actuator motors can occasionally require calibration.
Initial major fluid refresh, including specialized DCT transmission oil.
Spark plug replacement and secondary inspection of the high-performance cooling system.
Significant milestone covering differential fluid changes and comprehensive belt inspections.
Verify the service history specifically highlights the use of approved Mercedes-Benz high-performance engine oil.
Ensure all software updates for the MBUX infotainment and engine management have been performed by an authorized agent.
Keep a close watch on brake pad thickness; these performance rotors and pads are designed to stop hard and wear accordingly.
Regularly clear the front grille and air intakes of debris to maintain optimal airflow for the intercooler.
Check for any signs of weeping around the cooling system hoses, which is common in high-output turbo units.
Estimated repair costs if issues arise
Given the stopping power of the A45 S, the rotors and pads are high-performance items. Depending on your driving style, you might eventually need to budget for a premium set to maintain that factory feel.
The dual-clutch transmission is incredibly quick, but if this component needs attention in the future, it is a complex job best handled by specialists. It is worth keeping a rainy-day fund for long-term transmission health.
The A45 S is quite demanding on tires due to the 4MATIC+ grip. Depending on how much 'fun' you have on the weekends, you might eventually need to budget for a quality set of matching performance tires.
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Disclaimer: This report is generated with the assistance of AI analysis based on verified automotive data. While we strive for 100% accuracy, enthusiasts should always conduct physical inspections and consult service records. View Full Disclaimer