BMW's iconic saloon meets the sleek coupe. Which one is right for you? We compare real 2025 UK enquiry data, reliability, running costs, and ownership experience to give you an honest verdict.
The 3 Series wins for most buyers — it's more practical, cheaper to buy, and offers a wider range of engines and bodystyles. The 4 Series is the style choice: a sleek coupe or convertible with sharper looks and slightly sportier handling, but you'll pay more for the privilege.
Full spec comparison, deep dives, and which to choose for your lifestyle below.
| 3 Series (F30/F31) | 4 Series (F32/F33/F36) | |
|---|---|---|
| Body Styles | Saloon (F30), Touring (F31) | Coupe (F32), Convertible (F33), Gran Coupe (F36) |
| 2025 UK Enquiries | 380 [EM-VERIFIED] | 120 [EM-VERIFIED] |
| Primary Engine | N47D20C / B47D20A / B48B20 | N47D20C / B47D20A / B48B20 |
| Recon Supply Cost | £3,200–£5,500 | £2,800–£4,500 |
| Defining Failure | N47 timing chain (pre‑2015) | N47 timing chain (pre‑2015) |
| Best For | Practicality, value, four doors | Styling, driving dynamics, value retention |
The 3 Series takes the win for most buyers. It's the practical, affordable choice with four doors, a bigger boot, and a huge range of engines. The 4 Series is the style choice — lower, wider, and sleeker, with a more engaging driving experience. But for most people, the 3 Series' extra practicality and lower purchase price make it the smarter buy. That said, if you want a coupe or convertible and you're willing to pay the premium, the 4 Series is a brilliant car.
The 3 Series is BMW's best-selling model for good reason. It's practical, comfortable, and offers a wide range of engines from economical diesels to punchy six‑cylinders. Our data shows 380 enquiries for the F30 in 2025 [EM-VERIFIED], making it one of the most‑enquired models in the BMW range. Early models (pre‑2015) use the N47D20C diesel with its notorious timing chain stretch risk — see our N47 Timing Chain Failure page. Later models (2015‑on) get the B47D20A or B48B20 petrol, both of which are significantly more reliable. The 3 Series is also available as a Touring (F31) estate, adding even more practicality. It's a great all‑rounder — comfortable, spacious, and affordable. Full specs and reliability on the N47 Knowledge Centre and B47 Knowledge Centre.
The 4 Series is BMW's sleek coupe and convertible, plus the more practical Gran Coupe (F36) — a five‑door liftback that combines coupe styling with hatchback practicality. Enquiry volumes for the F32 are 120 in 2025 [EM-VERIFIED], reflecting a more niche audience. Like the 3 Series, early models use the N47D20C with its timing chain risk, but later models (2015‑on) get the B47D20A or B48B20, which are more reliable. The 4 Series is lower, wider, and sportier than the 3 Series, with sharper handling and a more premium feel. It holds its value better than the 3 Series, but it's more expensive to buy and insure. Our B47 vs N47 comparison covers the engine differences in more detail. If you want a stylish, sporty BMW that stands out, the 4 Series is hard to beat.
The biggest cost difference between these two isn't fuel or servicing — it's depreciation and the probability of a major engine failure. The 3 Series is cheaper to buy used, and parts are widely available, but the N47 timing chain risk on pre‑2015 models can be a £650‑£1,800 bill [PATTERN DATA]. The 4 Series holds its value better (coupe/convertible styling always does), but it costs more upfront and typically has higher insurance premiums. On average, the 3 Series costs less to own over five years, but the 4 Series' value retention can offset some of that difference.
3 Series — four doors, bigger boot, cheaper to buy and run. The practical choice.
4 Series — sleeker, sportier, more premium. The style choice, especially in coupe form.
3 Series — cheaper to buy, parts are more common, and insurance is typically lower.
4 Series — coupes and convertibles hold value better than saloons. A good long‑term bet.
The 3 Series and 4 Series share the same core engines and platforms, so the decision really comes down to bodystyle and driving preference. The 4 Series is the more exciting car; the 3 Series is the more sensible one. Both are excellent used buys, but whichever you choose, avoid pre‑2015 N47 engines unless you have a full timing chain history.
It depends on the engine. Both are reliable with the B47 diesel (post‑2015) or B48 petrol. The N47 in pre‑2015 models of both has a timing chain risk, so avoid it unless the chain has been done.
The 3 Series is cheaper to buy and generally cheaper to service, as parts are more common. The 4 Series has slightly higher tyre and brake wear due to its sportier setup, but fuel economy is similar.
Mostly, yes — they share the same platform and engines. The 4 Series is lower, wider, and has a sportier suspension setup, giving it sharper handling and a more planted feel.
The 4 Series coupe and convertible generally hold value better than the 3 Series saloon, due to coupe styling and desirability.
Real 2025 DataBoth models analysed from 24,650 UK enquiries.
Honest VerdictWe name a winner and explain why — and when the 'loser' is still the right choice.
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