# BMW 4 Series — Used Car Buying Guide

AutoScout's analysis of the BMW 4 Series on the UK used-car market. Backed by 33 million DVSA MOT tests, current AutoTrader pricing, and depreciation curves derived from CAP/Glass's Guide data.

Live interactive report: https://autoscout.fyi/cars/bmw-4-series

## Verdict

- **Best value year**: 2021
- **Ideal trim**: M Sport
- **Target mileage**: 35,000–55,000 miles
- **Max previous owners**: 2
- **Target price**: £23,500

## Why this model

The BMW 4 Series is a fantastic choice if you're looking for a stylish, sporty coupe that's also practical enough for daily driving. It offers a great balance of performance, premium interior quality, and that classic BMW driving feel. The 2021 model is part of the newer G22 generation, which means you get modern tech and a refined ride, but it's already taken the biggest hit on depreciation, making it much better value than buying new.

## What you should pay

Based on current UK market data for a 2021 BMW 420i M Sport with around 40,000 miles, you should aim to pay in the region of £22,000-£24,500. Prices can vary a bit depending on specific options, condition, and exact mileage, but this range gives you a solid benchmark. Be prepared to negotiate, especially if the car has been on the forecourt for a while.

## Which trim to buy

The M Sport trim is definitely the one to go for. It adds a much more aggressive and stylish exterior with sportier bumpers and larger alloy wheels, plus you get a more engaging driving experience thanks to the M Sport suspension. Inside, you'll find sports seats, a thicker M Sport steering wheel, and upgraded interior trim. It really completes the premium sports coupe feel and holds its value better than the standard Sport trim.

## What to check before you buy

- iDrive system glitches (often resolved with software updates)
- Suspension components wear (bushes, linkages, especially on sportier models)
- Minor electrical issues (sensors, warning lights)
- Brake wear (can be accelerated by driving style on M Sport models)

## Running costs

Fuel will be around 15-16p per mile for the 420i, so for 10,000 miles a year, budget about £1,500-£1,600. Road tax for a 2021 petrol model is £180 annually. Insurance can be a bit higher for a premium coupe, so expect to pay anywhere from £700 to £1,200+ depending on your age, location, and driving history. Servicing costs are moderate for a premium brand.

## Key stats

- **Fuel Type**: Petrol
- **Horsepower**: 184hp
- **Mpg**: 42 mpg
- **Reliability Score**: Good (7/10)
- **Safety Rating**: 5 Stars (Euro NCAP 2019)

## Trim comparison

| Trim | Price new | Price used | Key features |
| --- | --- | --- | --- |
| 420i Sport | £39,000 | £21,500 | 18-inch alloy wheels; LED headlights; Sport seats |
| 420i M Sport | £42,000 | £23,500 | 19-inch M light alloy wheels; M Sport suspension; M Aerodynamic bodystyling |
| 430i M Sport | £46,000 | £26,500 | More powerful 2.0L 258hp engine; Adaptive M Suspension; M Sport differential |

## Depreciation forecast

| Year | Estimated value | Retention |
| --- | --- | --- |
| 2026 | £22,990 | 100% |
| 2027 | £20,691 | 90% |
| 2028 | £19,035 | 82.8% |
| 2029 | £17,703 | 77% |
| 2030 | £16,641 | 72.4% |

Buying a 2021 model means you're getting the car after its steepest depreciation period. The initial drop in value from new has already happened, so your annual depreciation loss will be much slower compared to buying a newer model. This makes it a smart financial move for a premium car.

Total value lost since new: 27.6%.

## Alternatives to consider

- Audi A5 Coupe
- Mercedes-Benz C-Class Coupe
- [Lexus RC](https://autoscout.fyi/cars/lexus-rc.md)

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Source: AutoScout (https://autoscout.fyi). Part of a review of the UK used-car market across 500+ models.