Audi A4 vs BMW 4 Series
Figures updated
The Audi A4 and BMW 4 Series are two of the UK's most popular executive cars. We compare the B9 (2015–2024) A4 and the G22 (2020–) 4 Series on price, size, boot space, performance, safety and running costs, plus how reliable each has been across 348,858 real MOT tests.
The short answer
Pick the Audi A4 for the bigger boot, or the BMW 4 Series for the better MOT record and more performance.
- The Audi A4 has the biggest boot: 460 litres, 20 more than the BMW 4 Series.
- The BMW 4 Series has the better MOT record. Like for like on age and mileage, the Audi A4 fails its MOT about 10% more often.
- Watch the tyres on a BMW 4 Series: it fails on them 1.3 times as often as the average car.
| Figure | Audi A4B9 (2015–2024), 4-door saloon | BMW 4 SeriesG22 (2020–), 2-door coupé |
|---|---|---|
| Price and practicality | ||
| Price newUK list prices, across the range | – | £46,180 to £63,385July 2026 price list |
| Body | 4-door saloon | 2-door coupé |
| Seats | 5 (best) | 4 |
| BootSeats up / folded | 460 litres (best) | 440 litres |
| Length | 4,762mm | 4,768mm |
| WidthWithout mirrors | 1,847mm | 1,852mm |
| Height | 1,387mm | 1,383mm |
| Performance | ||
| Power | 136–265 PS | 184–374 PS (best) |
| 0–62mph | 5.5–9.5 sec | 4.5–7.5 sec (best) |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2015) | ★★★★★ (2019) |
| Economy and emissions | ||
| Fuel types | Diesel | Petrol |
| Official economyVersions of this generation | 54.3–74.3 mpg | 32.8–42.8 mpg |
| CO2 | 99–137 g/km | 144–186 g/km |
| Running costs at 7,500 miles a year | ||
| Petrol or hybrid171.7p a litre, today's UK average | – | £1,453 (40.3 mpg) |
| Diesel198.4p a litre | £1,030 (65.7 mpg) | – |
| Cheapest version to fuelWhichever fuel costs least | £1,030 (diesel) | £1,453 (petrol) |
| Car tax, registered 2001 to 2017Taxed on CO2; newer cars pay a flat £200 | £20 to £790 | £20 to £410 |
| Reliability from real MOT tests | ||
| Reliability score | 125Well above average | 138Well above average (best) |
| Failed MOT first time (ages 3–20) | 27.1% | 16.4% (best) |
| Failed at 3 years old | 11.8% (best) | 13.1% |
| Failed at 5 years old | 14.5% | 14.0% (best) |
| Failed at 10 years old | 26.3% | 21.6% (best) |
| Most common MOT fault | Coil spring (3.6% of tests) | Condition (2.4% of tests) |
| Fails more than average on | Nothing stands out | Tyres (1.3×) |
| MOT tests analysed | 244,913 | 103,945 |
| About the cars | ||
| Type | Executive car | Executive car |
| Owners' average miles a year | 9,900 | 9,200 |
| On sale | 2015–2024 | 2020 on |
Green marks the better figure where the difference is more than 3%. Reliability figures cover every version of each model tested in the year. Running costs use the typical official economy of recent versions (WLTP where available); real-world economy is usually a little worse for every car.
More comparisons
Frequently asked questions
›Is the Audi A4 or the BMW 4 Series more reliable?
The BMW 4 Series. Like for like on age and mileage, the Audi A4 fails its MOT about 10% more often (reliability scores 138 and 125, where 100 is average). 16.4% of BMW 4 Serieses and 27.1% of Audi A4s failed first time in 2024.
›Which is bigger, the Audi A4 or the BMW 4 Series?
They're almost the same length (4,762mm and 4,768mm). The Audi A4 has the bigger boot: 460 litres against 440.
›Which is safer, the Audi A4 or the BMW 4 Series?
Euro NCAP gave the Audi A4 5 stars (2015) and the BMW 4 Series 5 stars (2019). Euro NCAP makes its tests tougher every few years, so ratings from different years aren't directly comparable.
›Should I buy the Audi A4 or the BMW 4 Series?
Pick the Audi A4 for the bigger boot, or the BMW 4 Series for the better MOT record and more performance. The comparison above sets out price, space, performance, safety, running costs and reliability side by side.
Sources: manufacturers' UK specifications and price lists and Euro NCAP (listed on each model's page); DVSA anonymised MOT tests 2024 (Open Government Licence v3.0); Vehicle Certification Agency car fuel data, © Crown copyright, VCA cannot accept liability for its accuracy; fuel prices from the GOV.UK Fuel Finder scheme. Photos from Wikimedia Commons, credited under each picture.