Audi A4 B9 (8W) (2015 – 2025)

Reliability score : 8.4/10

The Audi A4 B9 (Typ 8W) represents a significant leap in refinement, technology, and reliability over its predecessor (the B8). Built on the MLB Evo platform, it shed up to 120 kg while improving structural rigidity. The B9 generation is widely regarded as one of the most reliable modern Audi models, largely because it benefits from the heavily revised EA888 Gen 3 and Gen 4 petrol engines, which finally resolved the notorious piston ring and oil consumption issues of the past. It received a minor update in 2018 and a major facelift (B9.5) in 2019, introducing mild-hybrid (MHEV) technology across most of the range and a touchscreen MMI system. Overall, it is a highly competent, quiet, and well-built premium compact executive car.

✅ Strengths

EA888 Gen 3/4 2.0 TFSI engines are exceptionally reliable and have cured the oil burning stigma of older Audis.
Class-leading interior build quality and material fitment, resisting creaks and rattles even at high mileage.
Excellent NVH (Noise, Vibration, Harshness) insulation, making it a superb highway cruiser.
The 7-speed S tronic (DL382) is highly durable provided the 60k km service intervals are strictly respected.
Strong rust prevention and high-quality exterior paint.

⚠️ Weaknesses

Water pump and thermostat housing leaks are the most common failure point on the 2.0 TFSI.
Catastrophic rocker arm failures on early (2017-2018) 3.0 V6 TFSI engines (S4/SQ5).
Belt Starter Generator (BSG) failures on 48V Mild-Hybrid models (V6 engines) can leave the car stranded and are very expensive to replace.
Front suspension control arm bushings tend to crack and tear around 80,000 - 100,000 km.
MMI infotainment screen can suffer from delamination or software freezing on pre-facelift models.

🎯 Verdict

The Audi A4 B9 is a highly recommended purchase and stands as one of the most reliable German premium cars of its era, provided you choose the right engine. The 2.0 TFSI (40 or 45 TFSI) is the absolute sweet spot, offering excellent performance, great fuel economy, and robust reliability (with only the water pump to keep an eye on). Buyers looking at the S4 (3.0 V6 TFSI) must exercise extreme caution with 2017-2018 models due to the rocker arm defect; aim for a late 2018 or newer model. Always insist on a full service history, particularly for the S tronic transmission.