BMW 3 Series vs Audi A4
Figures updated
The BMW 3 Series and Audi A4 are two of the UK's most popular executive cars. We compare the 3 Series G20 (2019–) and the B9 (2015–2024) A4 on price, size, boot space, performance, safety and running costs, plus how reliable each has been across 698,305 real MOT tests.
The short answer
The BMW 3 Series comes out ahead, with the bigger boot, the better MOT record and more performance; the Audi A4 is close on everything else.
- The BMW 3 Series has the biggest boot: 480 litres, 20 more than the Audi A4.
- The BMW 3 Series has the better MOT record. Like for like on age and mileage, the Audi A4 fails its MOT about 7% more often.
- Watch the wheels on a BMW 3 Series: it fails on them 2.3 times as often as the average car.
| Figure | BMW 3 Series3 Series G20 (2019–), 4-door saloon | Audi A4B9 (2015–2024), 4-door saloon |
|---|---|---|
| Price and practicality | ||
| Price newUK list prices, across the range | £41,945 to £66,475July 2026 price list | – |
| Body | 4-door saloon | 4-door saloon |
| Seats | 5 | 5 |
| BootSeats up / folded | 480 litres (best) | 460 litres |
| Length | 4,709mm | 4,762mm |
| WidthWithout mirrors | 1,827mm | 1,847mm |
| Height | 1,435mm | 1,387mm |
| Performance | ||
| Power | 150–374 PS (best) | 136–265 PS |
| 0–62mph | 4.4–8.4 sec (best) | 5.5–9.5 sec |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2019) | ★★★★★ (2015) |
| Economy and emissions | ||
| Fuel types | Petrol, Plug-in hybrid | Diesel |
| Official economyVersions of this generation | 32.8–42.1 mpg | 54.3–74.3 mpg |
| CO2 | 19–182 g/km | 99–137 g/km |
| Running costs at 7,500 miles a year | ||
| Petrol or hybrid171.4p a litre, today's UK average | £1,450 (40.3 mpg) | – |
| Diesel198.4p a litre | – | £1,030 (65.7 mpg) |
| Cheapest version to fuelWhichever fuel costs least | £1,450 (petrol) | £1,030 (diesel) |
| Car tax, registered 2001 to 2017Taxed on CO2; newer cars pay a flat £200 | £20 to £790 | £20 to £790 |
| Reliability from real MOT tests | ||
| Reliability score | 134Well above average (best) | 125Well above average |
| Failed MOT first time (ages 3–20) | 24.5% (best) | 27.1% |
| Failed at 3 years old | 14.0% | 11.8% (best) |
| Failed at 5 years old | 13.4% (best) | 14.5% |
| Failed at 10 years old | 24.8% (best) | 26.3% |
| Most common MOT fault | Tread depth (2.8% of tests) | Coil spring (3.6% of tests) |
| Fails more than average on | Wheels (2.3×) | Nothing stands out |
| MOT tests analysed | 453,392 | 244,913 |
| About the cars | ||
| Type | Executive car | Executive car |
| Owners' average miles a year | 9,700 | 9,900 |
| On sale | 2019 on | 2015–2024 |
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 BMW 3 Series or the Audi A4 more reliable?
The BMW 3 Series. Like for like on age and mileage, the Audi A4 fails its MOT about 7% more often (reliability scores 134 and 125, where 100 is average). 24.5% of BMW 3 Serieses and 27.1% of Audi A4s failed first time in 2024.
›Which is bigger, the BMW 3 Series or the Audi A4?
The Audi A4 is 53mm longer (4,762mm against 4,709mm). The BMW 3 Series has the bigger boot: 480 litres against 460.
›Which is safer, the BMW 3 Series or the Audi A4?
Euro NCAP gave the BMW 3 Series 5 stars (2019) and the Audi A4 5 stars (2015). Euro NCAP makes its tests tougher every few years, so ratings from different years aren't directly comparable.
›Should I buy the BMW 3 Series or the Audi A4?
The BMW 3 Series comes out ahead, with the bigger boot, the better MOT record and more performance; the Audi A4 is close on everything else. 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.