About the Audi A4 B9
AI-generatedThe Audi A4 B9 (2015-present) represents the fifth generation of Audi's executive saloon and estate (Avant) range. Built on the MLB Evo platform shared with the Q7, it's lighter yet more spacious than its predecessor, offering a premium cabin with Audi's Virtual Cockpit digital instrumentation. Available with a range of efficient four-cylinder petrol and diesel engines, plus powerful six-cylinder S4 variants, the B9 emphasises technology, refinement and build quality. This generation brought significant updates in 2019 with a facelift that introduced revised styling, updated infotainment with dual touchscreens, mild-hybrid technology on many engines, and improved driver assistance systems. The B9 A4 competes directly with the BMW 3 Series and Mercedes-Benz C-Class, offering a blend of understated elegance, strong residuals and that trademark Audi interior quality. It's available in SE, Sport, S line and Black Edition trims, with the high-performance S4 and ultra-efficient 'ultra' diesel models also part of the range.
Known Issues
Known Issues
B9 (2015-present)
2015-present
- Pre-facelift MMI infotainment can be slow to respond and occasionally freezes requiring a hard reset
- 2.0 TDI engines (2015-2018) may suffer from oil dilution issues if used mainly for short journeys
- Virtual Cockpit screen can develop pixel failures or complete blackouts, expensive to replace (£800-£1,200)
- Electronic parking brake faults causing warning lights and brake binding, often requires module replacement
- DAB radio aerial can fail causing poor reception, particularly on 2015-2017 models
- Dual-clutch S tronic gearbox mechatronic unit failures on early models, symptoms include jerky changes and loss of gears
- Water ingress into LED headlight units causing condensation and potential electrical faults
- Suspension knock from worn anti-roll bar bushes and drop links, common after 40,000 miles
- Diesel Particulate Filter (DPF) blocking on low-mileage diesel models used for urban driving
- Emissions system faults including AdBlue sensor failures and NOx sensor issues on post-2016 diesels
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Running Costs
Running Costs
Annual Fuel
£1,400-£2,200
Insurance Group
21-35
Average Service
£350-£500
Cost Calculator
Typical Prices
£26,000 - £35,000
£19,000 - £27,000
£15,000 - £22,000
£10,000 - £14,000
Pros & Cons
Pros & Cons
Pros
- Outstanding interior build quality with premium materials throughout
- Refined and comfortable ride, excellent for long motorway journeys
- Spacious cabin with generous rear legroom for the class
- Strong engine range with efficient diesels and punchy petrols
- Virtual Cockpit digital instrumentation is intuitive and highly configurable
- Impressive fuel economy, particularly from the 2.0 TDI ultra models achieving 60+ mpg
Cons
- Pre-facelift MMI infotainment system feels dated and can be laggy
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Best & Worst Years
Best & Worst Years
Best Years
- 2020 - Post-facelift model with improved dual-touchscreen MMI, mild-hybrid engines, updated styling and resolved early teething problems. Most refined and reliable B9 variant.
- 2019 - Major facelift year introducing significant technology upgrades, improved infotainment system and mild-hybrid powertrains, but still available at reasonable prices.
Worst Years
- 2016 - Early production model with higher incidence of S tronic gearbox issues, MMI software problems and electronic gremlins before software updates were rolled out.
- 2015 - Launch year with initial quality control issues, software bugs in Virtual Cockpit and infotainment, plus early diesel engines affected by oil dilution problems.
Buying Checklist
Engine6 items
- Check for oil leaks around cam cover and turbo oil feed pipes
- Listen for timing chain rattle on cold start (petrol engines)
- Ensure diesel engines start smoothly without excessive smoke
- Check AdBlue system functionality on post-2016 diesels - top up warning should not be present
- Verify oil level is correct and oil appears clean - low or dirty oil suggests poor maintenance
Did You Know?
Did You Know?
The B9 A4 is up to 120kg lighter than the B8 it replaced, thanks to extensive use of aluminium and high-strength steel
Audi's Virtual Cockpit was first introduced on the B9 A4, allowing drivers to display navigation maps across the entire instrument cluster
The 2019 facelift models feature mild-hybrid technology that can coast with the engine off and provides an extra 12bhp boost under acceleration
All B9 A4 models come with electromechanical power steering that can be switched off at speeds above 37mph to improve efficiency
Alternatives to Consider
BMW 3 Series (G20)
7/10More engaging to drive with sharper handling, similar build quality and running costs. Better driving dynamics but slightly less refined interior.
Mercedes-Benz C-Class (W205)
7/10Main premium rival with equally luxurious interior, comfortable ride and strong diesel engines. Similar pricing and running costs.
Jaguar XE
6/10More affordable alternative with distinctive styling and excellent handling. Less practical interior but potentially better value used.
Owner Tips
- 1Always ensure diesel models have been driven regularly on longer journeys to prevent DPF issues - check service history for regeneration warnings
- 2Budget for main dealer servicing or specialist Audi independents with proper diagnostic equipment - generic garages may struggle with complex electronics
- 3Check the Virtual Cockpit thoroughly during test drives for any pixel issues or flickering, as replacement is expensive
- 4On pre-2019 models, ensure all MMI software updates have been applied by an Audi dealer to fix known bugs
- 5Test the electronic parking brake multiple times - it should engage and disengage smoothly without grinding noises
- 6For used purchases, consider models with Audi's Approved Used warranty due to potential high repair costs
- 7Mild-hybrid models (2019 onwards) are more complex but more efficient - ensure the 12V starter-battery and 48V system are healthy
- 8
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