Audi A4(B9 – 2015-2024)
2015–2024 | Saloon, Avant, Allroad
Key Facts
- •Excellent premium build quality with strong residual values
- •Wide engine range: 2.0 TDI diesel is most popular and economical (50-60 mpg)
- •Annual servicing costs £300-£600 at authorised dealers; independents from £180
- •Insurance groups range from 22 (entry diesel) to 43 (S4 performance)
- •Common issues: DSG gearbox judder, timing chain stretch on petrol engines, DPF problems
Overview
The Audi A4 (B9 generation) was launched in 2015 and remains one of the UK's best-selling executive saloons. Available as a saloon or Avant estate, it competes with the BMW 3 Series and Mercedes C-Class. It offers a sophisticated interior with Audi's Virtual Cockpit, quattro all-wheel drive on higher trims, and a range of turbocharged petrol and diesel engines. The S4 and RS4 performance variants add significant performance credentials to the range.
Reliability
The Audi A4 B9 is generally reliable, scoring around 65/100 for reliability. The 2.0 TDI diesel engine is particularly proven with hundreds of thousands of examples on UK roads. However, owners should watch for timing chain stretch on the 2.0 TFSI petrol engine, DSG S-Tronic gearbox shudder at low speeds, and DPF (diesel particulate filter) issues if used mainly for short journeys.
Running Costs
Fuel economy: 2.0 TDI (45-60 mpg combined), 2.0 TFSI (35-45 mpg), S4 V6 (28-35 mpg). Road tax VED: from £20/year for low-emission versions (pre-April 2017) to standard £190/year. Annual servicing: £300-£600 (dealer), £180-£350 (independent). Insurance: £800-£2,500 annually depending on driver profile and trim level.
MOT Reliability
The Audi A4 B9 performs reasonably well on MOT tests with an approximate pass rate of 72% on first attempt. Common MOT issues include: brake wear (especially rear on quattro models), tyre wear (often uneven due to quattro system), suspension bush deterioration after 60,000 miles, and DPF warning lights triggering MIL failures. Maintaining service intervals significantly improves MOT pass rates.
Common Problems
1. Timing chain stretch (2.0 TFSI petrol, pre-2016): Can cause engine failure if not addressed early. Listen for a rattling sound on cold starts. Fix: timing chain replacement (£800-£1,500). 2. DSG/S-Tronic judder: Low-speed shudder or judder especially when pulling away. Fix: Mechatronic unit service or replacement (£500-£1,500). 3. DPF blockage: Short journey usage blocks the DPF filter. Symptoms: DPF warning light, reduced power. Fix: forced regeneration or replacement (£200-£1,500). 4. Sunroof drainage: Blocked drainage channels cause water ingress. Regular cleaning prevents this.
Insurance
The Audi A4 sits in insurance groups 22-43 depending on specification. The entry-level 35 TDI sits in group 22-26, offering relatively affordable insurance. The 40 TFSI petrol and S4 3.0 V6 rise to groups 38-43. Expect annual premiums of £800-£2,500 depending on your profile, age, and location. Security features including Audi's tracking system can reduce premiums.
Road Tax (VED)
VED road tax varies significantly by engine and registration year. Pre-April 2017 A4s with CO2 under 100g/km can benefit from very low or zero road tax. From April 2017 onwards, most A4 variants pay the standard rate of £190/year. The RS4 and petrol versions with higher CO2 may have a premium rate during the first year based on list price.
Maintenance & Servicing
Service intervals: Variable service (VSI) system, typically 10,000-18,000 miles or 12 months. Minor service: oil change + filter (£180-£300). Major service: full inspection + fluids (£350-£600). Cambelt: Not required (chain-driven). DSG fluid change: recommended every 40,000 miles (£200). Brake fluid: every 2 years (£60-£80). DSG models are more complex—use VAG-specialist for best value.
Frequently Asked Questions
Is the Audi A4 reliable?
The Audi A4 B9 (2015-2024) is generally reliable with a reliability score of around 65/100. The 2.0 TDI diesel is particularly robust, though all variants need regular servicing to maintain reliability. Key issues to watch for are timing chain stretch (petrol), DSG judder, and DPF problems.
What's the most reliable Audi A4 engine?
The 2.0 TDI 150hp diesel is widely regarded as the most reliable and economical A4 engine. It's proven in many applications with over a million examples globally. The TFSI petrol engines are also reliable but require stricter oil-change discipline.
What's the Audi A4 insurance group?
The Audi A4 sits in insurance groups 22-43 depending on specification. Entry-level diesels start around group 22, mid-range 40 TFSI models are around group 30-35, and the performance S4 is around group 40-43.
How much does it cost to service an Audi A4?
An Audi A4 service costs £180-£300 for a minor service (oil and filter) and £350-£600 for a major service at an independent VAG specialist. Audi dealers charge significantly more—typically £400-£800 for major services.
What are common Audi A4 problems?
The most common Audi A4 B9 problems are: DSG S-Tronic gearbox judder, timing chain stretch on petrol engines (especially pre-2016), DPF blockage in diesels used for short journeys, and suspension bush wear after 60,000 miles.
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