Audi A4 vs Audi A5
Figures updated
The Audi A4 and Audi A5 are two of the UK's most popular executive cars. We compare the B9 (2015–2024) A4 and the B10 (2024–) A5 on price, size, boot space, performance, safety and running costs, plus how reliable each has been across 369,082 real MOT tests.
The short answer
Pick the Audi A4 for lower fuel costs, or the Audi A5 for the better MOT record.
- Their boots are much the same size: Audi A4 460 litres, Audi A5 445 litres.
- The Audi A5 has the better MOT record. Like for like on age and mileage, the Audi A4 fails its MOT about 8% more often.
- The Audi A4 is the cheapest to fuel: comparing diesel versions, about £191 a year less than the Audi A5 at 7,500 miles a year.
| Figure | Audi A4B9 (2015–2024), 4-door saloon | Audi A5B10 (2024–), 5-door hatchback |
|---|---|---|
| Price and practicality | ||
| Price newUK list prices, across the range | – | from £42,760October 2026 price list |
| Body | 4-door saloon | 5-door hatchback |
| Seats | 5 | 5 |
| BootSeats up / folded | 460 litres (best) | 445 litres / 1,299 |
| Length | 4,762mm | 4,829mm |
| WidthWithout mirrors | 1,847mm | 1,860mm |
| Height | 1,387mm | 1,444mm |
| Performance | ||
| Power | 136–265 PS | up to 299 PS (best) |
| 0–62mph | 5.5–9.5 sec (best) | from 5.9 sec |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2015) | ★★★★★ (2024) |
| Economy and emissions | ||
| Fuel types | Diesel | Diesel, Hybrid, Petrol, Plug-in hybrid |
| Official economyVersions of this generation | 54.3–74.3 mpg | 38.7–57.6 mpg |
| CO2 | 99–137 g/km | 46–166 g/km |
| Running costs at 7,500 miles a year | ||
| Petrol or hybrid171.8p a litre, today's UK average | – | £1,411 (41.5 mpg) |
| Diesel198.4p a litre | £1,030 (65.7 mpg) (best) | £1,221 (55.4 mpg) |
| Cheapest version to fuelWhichever fuel costs least | £1,030 (diesel) | £1,221 (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 | 125Well above average | 135Well above average (best) |
| Failed MOT first time (ages 3–20) | 27.1% | 22.0% (best) |
| Failed at 3 years old | 11.8% (best) | 12.7% |
| Failed at 5 years old | 14.5% (best) | 15.0% |
| Failed at 10 years old | 26.3% | 23.8% (best) |
| Most common MOT fault | Coil spring (3.6% of tests) | Tread depth (3.4% of tests) |
| Fails more than average on | Nothing stands out | Nothing stands out |
| MOT tests analysed | 244,913 | 124,169 |
| About the cars | ||
| Type | Executive car | Executive car |
| Owners' average miles a year | 9,900 | 9,300 |
| On sale | 2015–2024 | 2024 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 Audi A5 more reliable?
The Audi A5. Like for like on age and mileage, the Audi A4 fails its MOT about 8% more often (reliability scores 135 and 125, where 100 is average). 22.0% of Audi A5s and 27.1% of Audi A4s failed first time in 2024.
›Which is bigger, the Audi A4 or the Audi A5?
The Audi A5 is 67mm longer (4,829mm against 4,762mm). Their boots are much the same: 460 and 445 litres.
›Which is cheaper to run, the Audi A4 or the Audi A5?
Comparing diesel versions, the Audi A4 costs about £191 a year less to fuel at 7,500 miles (£1,030 against £1,221), using typical official economy and current UK average fuel prices.
›Which is safer, the Audi A4 or the Audi A5?
Euro NCAP gave the Audi A4 5 stars (2015) and the Audi A5 5 stars (2024). 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 Audi A5?
Pick the Audi A4 for lower fuel costs, or the Audi A5 for the better MOT record. 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.