Used Vauxhall Astra K (2015–21) vs SEAT Leon Mk3 (2012–20)
Figures updated
Shopping for a used family hatchback? We compare the Vauxhall Astra K (2015–2021) and SEAT Leon Mk3 (2012–2020), which were on sale at the same time, on size, boot space, performance, safety and running costs, plus how cars of their age do in real MOT tests.
The short answer
The SEAT Leon Mk3 comes out ahead, with the better MOT record; the Vauxhall Astra K is close on everything else.
- Their boots are much the same size: Vauxhall Astra K 370 litres, SEAT Leon Mk3 380 litres.
- The SEAT Leon Mk3 has the better MOT record for its age: the SEAT Leon Mk3 fails its MOT 10% less often than average for its age (21% of SEAT Leons built 2012–2020 failed first time in 2024, against 24% of all cars that age), while the Vauxhall Astra K fails its MOT 7% more often than average for its age (23% of Vauxhall Astras built 2015–2021 failed first time in 2024, against 22% of all cars that age).
- Watch the exhaust and emissions on a Vauxhall Astra K: it fails on them 1.4 times as often as the average car.
| Figure | Vauxhall Astra KAstra K (2015–2021), 5-door hatchback | SEAT Leon Mk3Mk3 (2012–2020), 5-door hatchback |
|---|---|---|
| Price and practicality | ||
| Body | 5-door hatchback | 5-door hatchback |
| Seats | 5 | 5 |
| BootSeats up / folded | 370 litres / 1,210 | 380 litres |
| Length | 4,370mm | 4,263mm |
| WidthWithout mirrors | 1,809mm | 1,810mm |
| Height | 1,485mm | 1,446mm |
| Performance | ||
| Power | 100–200 PS (best) | 86–184 PS |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2015) | ★★★★★ (2012) |
| Economy and emissions | ||
| Fuel types | – | – |
| Official economyVersions of this generation | – | – |
| CO2 | – | – |
| Running costs at 7,500 miles a year | ||
| Cheapest version to fuelWhichever fuel costs least | – | – |
| Car tax, registered 2001 to 2017Taxed on CO2; newer cars pay a flat £200 | – | – |
| Reliability from real MOT tests | ||
| Reliability score | 99Average | 116Well above average (best) |
| Failed first time, cars of this generation's ageUK rate for cars the same age in brackets | 23.4% (22.0%)built 2015–2021 | 21.1% (23.6%)built 2012–2020 (best) |
| Failed MOT first time (ages 3–20) | 33.8% | 23.6% (best) |
| Failed at 3 years old | 12.4% | 12.3% |
| Failed at 5 years old | 17.9% | 18.3% |
| Failed at 10 years old | 32.8% | 24.3% (best) |
| Most common MOT fault | Coil spring (5.1% of tests) | Coil spring (2.8% of tests) |
| Fails more than average on | Exhaust and emissions (1.4×) | Nothing stands out |
| MOT tests analysed | 624,660 | 181,734 |
| About the cars | ||
| Type | Family hatchback | Family hatchback |
| Owners' average miles a year | 8,000 | 9,400 |
| On sale | 2015–2021 | 2012–2020 |
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 a used Vauxhall Astra K or SEAT Leon Mk3 more reliable?
The SEAT Leon Mk3. Compared with all cars the same age, the SEAT Leon Mk3 fails its MOT 10% less often than average and the Vauxhall Astra K 7% more often than average (DVSA MOT tests, 2024). Because they're different ages, their raw rates differ: 21.1% of SEAT Leons built 2012–2020 failed first time, and 23.4% of Vauxhall Astras built 2015–2021. Whatever you buy, check the MOT history of the exact car.
›Which is bigger, the Vauxhall Astra K or the SEAT Leon Mk3?
The Vauxhall Astra K is 107mm longer (4,370mm against 4,263mm). Their boots are much the same: 370 and 380 litres.
›Which is safer, the Vauxhall Astra K or the SEAT Leon Mk3?
Euro NCAP gave the Vauxhall Astra K 5 stars (2015) and the SEAT Leon Mk3 5 stars (2012). Euro NCAP makes its tests tougher every few years, so ratings from different years aren't directly comparable.
›Should I buy the Vauxhall Astra K or the SEAT Leon Mk3?
The SEAT Leon Mk3 comes out ahead, with the better MOT record; the Vauxhall Astra K 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.