BMW 3 Series vs Mercedes-Benz C-Class
Figures updated
The BMW 3 Series and Mercedes-Benz C-Class are two of the UK's most popular executive cars. We compare the 3 Series G20 (2019–) and the W206 (2021–) C-Class on price, size, boot space, performance, safety and running costs, plus how reliable each has been across 815,528 real MOT tests.
The short answer
The BMW 3 Series comes out ahead, with the lower price, the bigger boot, the better MOT record, lower fuel costs and more performance; the Mercedes-Benz C-Class is close on everything else.
- The BMW 3 Series is the cheapest to buy new: from £41,945, £5,050 less than the Mercedes-Benz C-Class.
- The BMW 3 Series has the biggest boot: 480 litres, 25 more than the Mercedes-Benz C-Class.
- The BMW 3 Series has the better MOT record. Like for like on age and mileage, the Mercedes-Benz C-Class fails its MOT about 12% more often.
- The BMW 3 Series is the cheapest to fuel: comparing petrol versions, about £80 a year less than the Mercedes-Benz C-Class at 7,500 miles a year.
- 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 | Mercedes-Benz C-ClassW206 (2021–), 4-door saloon |
|---|---|---|
| Price and practicality | ||
| Price newUK list prices, across the range | £41,945 to £66,475July 2026 price list (best) | £46,995 to £62,515September 2026 price list |
| Body | 4-door saloon | 4-door saloon |
| Seats | 5 | 5 |
| BootSeats up / folded | 480 litres (best) | 455 litres |
| Length | 4,709mm | 4,773mm |
| WidthWithout mirrors | 1,827mm | 1,820mm |
| Height | 1,435mm | 1,443mm |
| Performance | ||
| Power | 150–374 PS (best) | 218–258 PS |
| 0–62mph | 4.4–8.4 sec (best) | 5.9–7.3 sec |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2019) | ★★★★★ (2022) |
| Economy and emissions | ||
| Fuel types | Petrol, Plug-in hybrid | Diesel, Petrol, Plug-in hybrid |
| Official economyVersions of this generation | 32.8–42.1 mpg | 25.5–62.8 mpg |
| CO2 | 19–182 g/km | 10–253 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) (best) | £1,530 (38.2 mpg) |
| Diesel198.4p a litre | – | £1,221 (55.4 mpg) |
| Cheapest version to fuelWhichever fuel costs least | £1,450 (petrol) | £1,221 (diesel) |
| Car tax a yearCars registered from April 2017 | £200£640 in years 2–6 for versions listed over £40,000 | £200£640 in years 2–6 for versions listed over £40,000 |
| Reliability from real MOT tests | ||
| Reliability score | 134Well above average (best) | 120Well above average |
| Failed MOT first time (ages 3–20) | 24.5% (best) | 25.5% |
| Failed at 3 years old | 14.0% | 13.1% (best) |
| Failed at 5 years old | 13.4% | 13.8% |
| Failed at 10 years old | 24.8% (best) | 27.1% |
| Most common MOT fault | Tread depth (2.8% of tests) | Ball joint (4.5% of tests) |
| Fails more than average on | Wheels (2.3×) | Nothing stands out |
| MOT tests analysed | 453,392 | 362,136 |
| About the cars | ||
| Type | Executive car | Executive car |
| Owners' average miles a year | 9,700 | 8,900 |
| On sale | 2019 on | 2021 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 BMW 3 Series or the Mercedes-Benz C-Class more reliable?
The BMW 3 Series. Like for like on age and mileage, the Mercedes-Benz C-Class fails its MOT about 12% more often (reliability scores 134 and 120, where 100 is average). 24.5% of BMW 3 Serieses and 25.5% of Mercedes-Benz C-Classes failed first time in 2024.
›Which is bigger, the BMW 3 Series or the Mercedes-Benz C-Class?
The Mercedes-Benz C-Class is 64mm longer (4,773mm against 4,709mm). The BMW 3 Series has the bigger boot: 480 litres against 455.
›Which is cheaper to buy, the BMW 3 Series or the Mercedes-Benz C-Class?
The BMW 3 Series: new prices start at £41,945, £5,050 less than the Mercedes-Benz C-Class (from £46,995). These are manufacturer list prices; dealers and brokers often sell for less.
›Which is cheaper to run, the BMW 3 Series or the Mercedes-Benz C-Class?
Comparing petrol versions, the BMW 3 Series costs about £80 a year less to fuel at 7,500 miles (£1,450 against £1,530), using typical official economy and current UK average fuel prices.
›Which is safer, the BMW 3 Series or the Mercedes-Benz C-Class?
Euro NCAP gave the BMW 3 Series 5 stars (2019) and the Mercedes-Benz C-Class 5 stars (2022). 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 Mercedes-Benz C-Class?
The BMW 3 Series comes out ahead, with the lower price, the bigger boot, the better MOT record, lower fuel costs and more performance; the Mercedes-Benz C-Class 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.