Audi A4 B9: pros, cons, costs, alternatives
“second facelift” – Model-Year 2025
Audi’s midsize saloon/estate gets a final refresh before the next-gen “A5” arrives: sharper bumpers, a 3-D Singleframe grille, customisable Digital-LED head-lamps and the new 11.9-inch MIB 3.5 infotainment. The MLB-evo chassis, saloon and Avant bodies (4 760 mm long) and longitudinal powertrains stay untouched. Boot space is 460 L (Saloon) or 495 L (Avant, up to 1 495 L with the rear bench folded).
| Engine (EU-6e) | Output / Torque | 48 V M-HEV | Drive | Transmission |
|---|
| 35 TFSI 2.0 | 150 hp • 270 Nm | yes | FWD | 7-speed S tronic (wet) |
| 40 TFSI 2.0 | 204 hp • 320 Nm | yes | quattro | 7-speed S tronic |
| 45 TFSI 2.0 | 265 hp • 370 Nm | yes | quattro | 7-speed S tronic |
| 35 TDI 2.0 | 163 hp • 380 Nm | yes | FWD | 7-speed S tronic |
| 40 TDI 2.0 | 204 hp • 400 Nm | yes | quattro | 7-speed S tronic |
| S4 3.0 V6 TDI | 341 hp • 700 Nm | yes | quattro | 8-speed Tiptronic |
The 48-V belt-starter generator (12 kW) allows sailing up to 160 km/h and stop-go down to 22 km/h.
Strengths (forums & European road-tests)
| PRO | Why it convinces |
|---|
| Class-leading cabin quality | Soft-touch dashboard, open-pore wood or brushed aluminium trims, new 30-colour “Contour Plus” ambient lighting. |
| Effective mild-hybrid system | Real 6.1 L/100 km on 35/40 TFSI; 4.9 L on TDIs despite 1.7 t kerb mass. |
| Outstanding motorway hush | Cd 0.25 and optional double glazing: 68 dB measured at 130 km/h. |
| Balanced ride/handling with DCC | Plush on 18-inch wheels yet precise; quattro traction is peerless in the wet. |
| MMI 11.9″ + Virtual 12.3″ | Snappy interface, three-year free OTA maps, Amazon Alexa built in. |
| Robust residuals | Avant 40 TDI quattro S-line retains ~70 % of list after 3 years. |
Weaknesses (recurring owner feedback)
| CON | Reported detail |
|---|
| Ageing platform | Rivals (BMW 3-Series G20 LCI, Mercedes C-Class W206) offer curved displays and 400-V 48-V systems; A4 sticks to 12/48 V. |
| Pricey options | Matrix LEDs, DCC, leather pack and ACC Pro add €8-10 k to a base 35 TFSI. |
| Only “good” rear room | Ample legroom, but the bulky tunnel and low cushion hinder a fifth passenger. |
| Cold-start DSG shunt | Some 35 TFSIs judder below 20 km/h; software update mitigates but doesn’t erase it. |
| EA888 oil appetite | 0.4–0.6 L every 4 000 km deemed “within spec.” |
| MMI glitches after OTA | Occasional reboots cured by hard reset plus dealer patch. |
| Heavy S4 TDI | At 1 900 kg it’s less playful than petrol rivals; exhaust note is speaker-augmented. |
Running-cost snapshot
| Job | Parts (€) | Labour (€) | Interval |
|---|
| LongLife oil 0W-30 + filter | 180 | 110 | 30 000 km / 24 mo |
| Fuel filter (TDI) | 70 | 60 | 60 000 km |
| DSG oil & filter (DQ381) | 230 | 160 | 60 000 km |
| Brake fluid + Haldex (quattro) | 120 | 130 | every 3 yr |
| Belt + water-pump EA888 | 220 | 190 | 150 000 km / 6 yr |
| Front discs + pads 40 TDI | 320 | 150 | ~65 000 km |
Known issues & fixes
| Issue | Current remedy |
|---|
| Faulty NOx sensor (TDI) | ECU update and sensor replaced under extended warranty. |
| Passenger-side dash creak | Felt shims kit (TPI 2068372). |
| Steering shimmy >120 km/h (quattro) | Wheel balance + lower-arm bush check (TPI 2070458). |
| MMI OTA boot loop | 12 s reset, flash to SW 2860_12; head-unit replaced if persistent. |
| Matrix LED condensation | New vents from MY 24; lamp swapped free if moisture lasts >24 h. |
Price guide (OTR)
| Trim | Engine | Driveline / Gearbox | List price |
|---|
| A4 35 TFSI Business | 150 hp | FWD / 6-MT | €42 600 |
| A4 35 TFSI S-line S tronic | 150 hp | FWD / 7-DCT | €46 800 |
| A4 40 TDI quattro | 204 hp | AWD / 7-DCT | €50 900 |
| A4 45 TFSI quattro S-line | 265 hp | AWD / 7-DCT | €54 700 |
| S4 TDI quattro | 341 hp | AWD / 8-AT | €67 500 |
Add €1 400 for Avant. MY 22-23 Avant 40 TDI quattro S-lines with 40 k km retail around €40 k.
Verdict
Awaiting the next-gen plug-in “A5”, the 2025 A4 still mixes top-tier cabin quality, an updated infotainment suite, full ADAS and frugal mild-hybrid power-trains. Downsides are a decade-old platform, steep option pricing and a few software and DSG niggles.
For buyers prioritising motorway comfort, quattro security and rock-solid resale, an A4 Avant 40 TDI or 40 TFSI remains a benchmark. Shoppers chasing cutting-edge interiors, deep electrification or sharper dynamics may lean towards the newest 3-Series or C-Class instead.
Audi A4: pros, cons, costs and common fixes 
