BMW 3 Series vs BMW 4 Series
Figures updated
The BMW 3 Series and BMW 4 Series are two of the UK's most popular executive cars. We compare the 3 Series G20 (2019–) and the G22 (2020–) 4 Series on price, size, boot space, performance, safety and running costs, plus how reliable each has been across 557,337 real MOT tests.
The short answer
The BMW 3 Series comes out ahead, with the lower price and the bigger boot; the BMW 4 Series is close on everything else.
- The BMW 3 Series is the cheapest to buy new: from £41,945, £4,235 less than the BMW 4 Series.
- The BMW 3 Series has the biggest boot: 480 litres, 40 more than the BMW 4 Series.
- Their MOT records are close: once age and mileage are taken into account, they fail about as often as each other.
- Running costs are close: the petrol versions cost within £10 a year of each other to fuel 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.
- Watch the tyres on a BMW 4 Series: it fails on them 1.3 times as often as the average car.
| Figure | BMW 3 Series3 Series G20 (2019–), 4-door saloon | BMW 4 SeriesG22 (2020–), 2-door coupé |
|---|---|---|
| Price and practicality | ||
| Price newUK list prices, across the range | £41,945 to £66,475July 2026 price list (best) | £46,180 to £63,385July 2026 price list |
| Body | 4-door saloon | 2-door coupé |
| Seats | 5 (best) | 4 |
| BootSeats up / folded | 480 litres (best) | 440 litres |
| Length | 4,709mm | 4,768mm |
| WidthWithout mirrors | 1,827mm | 1,852mm |
| Height | 1,435mm | 1,383mm |
| Performance | ||
| Power | 150–374 PS | 184–374 PS |
| 0–62mph | 4.4–8.4 sec | 4.5–7.5 sec |
| Safety | ||
| Euro NCAP ratingTests get tougher each year | ★★★★★ (2019) | ★★★★★ (2019) |
| Economy and emissions | ||
| Fuel types | Petrol, Plug-in hybrid | Petrol |
| Official economyVersions of this generation | 32.8–42.1 mpg | 32.8–42.8 mpg |
| CO2 | 19–182 g/km | 144–186 g/km |
| Running costs at 7,500 miles a year | ||
| Petrol or hybrid171.6p a litre, today's UK average | £1,452 (40.3 mpg) | £1,452 (40.3 mpg) |
| Cheapest version to fuelWhichever fuel costs least | £1,452 (petrol) | £1,452 (petrol) |
| 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 | 138Well above average |
| Failed MOT first time (ages 3–20) | 24.5% | 16.4% (best) |
| Failed at 3 years old | 14.0% | 13.1% (best) |
| Failed at 5 years old | 13.4% (best) | 14.0% |
| Failed at 10 years old | 24.8% | 21.6% (best) |
| Most common MOT fault | Tread depth (2.8% of tests) | Condition (2.4% of tests) |
| Fails more than average on | Wheels (2.3×) | Tyres (1.3×) |
| MOT tests analysed | 453,392 | 103,945 |
| About the cars | ||
| Type | Executive car | Executive car |
| Owners' average miles a year | 9,700 | 9,200 |
| On sale | 2019 on | 2020 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 BMW 4 Series more reliable?
There's little in it. Once age and mileage are taken into account, both fail their MOT about as often as each other (reliability scores 134 and 138, where 100 is average).
›Which is bigger, the BMW 3 Series or the BMW 4 Series?
The BMW 4 Series is 59mm longer (4,768mm against 4,709mm). The BMW 3 Series has the bigger boot: 480 litres against 440.
›Which is cheaper to buy, the BMW 3 Series or the BMW 4 Series?
The BMW 3 Series: new prices start at £41,945, £4,235 less than the BMW 4 Series (from £46,180). These are manufacturer list prices; dealers and brokers often sell for less.
›Which is cheaper to run, the BMW 3 Series or the BMW 4 Series?
Comparing petrol versions, fuel costs are within £10 a year of each other at 7,500 miles, using typical official economy and current UK average fuel prices.
›Which is safer, the BMW 3 Series or the BMW 4 Series?
Euro NCAP gave the BMW 3 Series 5 stars (2019) and the BMW 4 Series 5 stars (2019). 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 BMW 4 Series?
The BMW 3 Series comes out ahead, with the lower price and the bigger boot; the BMW 4 Series 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.