Used Mercedes-Benz C-Class W205 (2014–21) vs BMW 5 Series G30 (2017–23)
Figures updated
Shopping for a used executive car? We compare the Mercedes-Benz C-Class W205 (2014–2021) and BMW 5 Series G30 (2017–2023), 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 BMW 5 Series G30 comes out ahead, with the better MOT record and lower fuel costs; the Mercedes-Benz C-Class W205 is close on everything else.
- The BMW 5 Series G30 has the better MOT record for its age: the BMW 5 Series G30 fails its MOT 25% less often than average for its age (13% of BMW 5 Serieses built 2017–2021 failed first time in 2024, against 17% of all cars that age), while the Mercedes-Benz C-Class W205 fails its MOT 16% less often than average for its age (19% of Mercedes-Benz C-Classes built 2014–2021 failed first time in 2024, against 22% of all cars that age).
- The BMW 5 Series G30 is the cheapest to fuel: comparing diesel versions, about £95 a year less than the Mercedes-Benz C-Class W205 at 7,500 miles a year.
- Watch the wheels on a BMW 5 Series G30: it fails on them 2.2 times as often as the average car.
| Figure | Mercedes-Benz C-Class W205W205 (2014–2021), 4-door saloon | BMW 5 Series G30G30 (2017–2023), 4-door saloon |
|---|---|---|
| Price and practicality | ||
| Body | 4-door saloon | 4-door saloon |
| Seats | – | 5 |
| BootSeats up / folded | – | 530 litres |
| Length | 4,686mm | 4,935mm |
| WidthWithout mirrors | 1,810mm | 1,868mm |
| Height | 1,442mm | 1,466mm |
| Performance | ||
| Power | – | 184–530 PS |
| 0–62mph | – | 3.8–7.9 sec |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2014) | ★★★★★ (2017) |
| Economy and emissions | ||
| Fuel types | Diesel | Diesel |
| Official economyVersions of this generation | 50.4–57.7 mpg | 50.4–68.9 mpg |
| CO2 | 129–146 g/km | 108–148 g/km |
| Running costs at 7,500 miles a year | ||
| Diesel198.4p a litre | £1,221 (55.4 mpg) | £1,126 (60.1 mpg) (best) |
| Cheapest version to fuelWhichever fuel costs least | £1,221 (diesel) | £1,126 (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 | 120Well above average | 157Well above average (best) |
| Failed first time, cars of this generation's ageUK rate for cars the same age in brackets | 18.6% (22.2%)built 2014–2021 | 13.0% (17.2%)built 2017–2021 (best) |
| Failed MOT first time (ages 3–20) | 25.5% | 20.3% (best) |
| Failed at 3 years old | 13.1% | 11.9% (best) |
| Failed at 5 years old | 13.8% | 12.5% (best) |
| Failed at 10 years old | 27.1% | 19.9% (best) |
| Most common MOT fault | Ball joint (4.5% of tests) | Tread depth (2.4% of tests) |
| Fails more than average on | Nothing stands out | Wheels (2.2×) |
| MOT tests analysed | 362,136 | 198,590 |
| About the cars | ||
| Type | Executive car | Executive car |
| Owners' average miles a year | 8,900 | 10,900 |
| On sale | 2014–2021 | 2017–2023 |
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 Mercedes-Benz C-Class W205 or BMW 5 Series G30 more reliable?
The BMW 5 Series G30. Compared with all cars the same age, the BMW 5 Series G30 fails its MOT 25% less often than average and the Mercedes-Benz C-Class W205 16% less often than average (DVSA MOT tests, 2024). Because they're different ages, their raw rates differ: 13.0% of BMW 5 Serieses built 2017–2021 failed first time, and 18.6% of Mercedes-Benz C-Classes built 2014–2021. Whatever you buy, check the MOT history of the exact car.
›Which is bigger, the Mercedes-Benz C-Class W205 or the BMW 5 Series G30?
The BMW 5 Series G30 is 249mm longer (4,935mm against 4,686mm).
›Which is cheaper to run, the Mercedes-Benz C-Class W205 or the BMW 5 Series G30?
Comparing diesel versions, the BMW 5 Series G30 costs about £95 a year less to fuel at 7,500 miles (£1,126 against £1,221), using typical official economy and current UK average fuel prices.
›Which is safer, the Mercedes-Benz C-Class W205 or the BMW 5 Series G30?
Euro NCAP gave the Mercedes-Benz C-Class W205 5 stars (2014) and the BMW 5 Series G30 5 stars (2017). Euro NCAP makes its tests tougher every few years, so ratings from different years aren't directly comparable.
›Should I buy the Mercedes-Benz C-Class W205 or the BMW 5 Series G30?
The BMW 5 Series G30 comes out ahead, with the better MOT record and lower fuel costs; the Mercedes-Benz C-Class W205 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.