# BMW 8 Series — Used Car Buying Guide

AutoScout's analysis of the BMW 8 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-8-series

## Verdict

- **Best value year**: 2021
- **Ideal trim**: 840d M Sport Gran Coupe
- **Target mileage**: 30,000–50,000 miles
- **Max previous owners**: 2
- **Target price**: £31,990

## Why this model

The BMW 8 Series Gran Coupe is a fantastic choice if you're looking for a blend of luxury, performance, and practicality in a stylish package. It offers a truly premium interior, a comfortable ride for long journeys, and enough space for four adults. The 840d diesel engine, in particular, provides impressive torque and surprisingly good fuel economy for such a large, powerful car, making it a sensible option for covering long distances without constant fuel stops. It's a proper grand tourer that feels special every time you get behind the wheel.

## What you should pay

Based on current UK market data for February 2026, a 2021 BMW 840d M Sport Gran Coupe with around 30,000-50,000 miles is typically trading around the £31,990 mark. Prices can vary a bit depending on specific options, condition, and exact mileage, but this is a solid target. You might find slightly older 2019-2020 models for a few thousand less, or very low mileage examples for a bit more, but stick close to this anchor for the best value.

## Which trim to buy

The 840d M Sport Gran Coupe is the sweet spot in the range. The 3.0-litre diesel engine offers a fantastic balance of power and efficiency, making it much more economical for daily driving and longer trips than the petrol 840i or the thirsty M850i V8. The 'M Sport' trim gives you all the sporty looks and handling upgrades (like adaptive M suspension) without the significantly higher running costs and purchase price of the full 'M' models. It also comes packed with luxury features as standard, so you won't feel like you're missing out.

## What to check before you buy

- Infotainment system glitches (iDrive)
- Potential for air suspension issues on some models
- Electrical gremlins (common with complex modern cars)
- High brake and tyre wear due to performance and weight
- Expensive parts and specialist labour costs

## Running costs

Running an 840d will involve a few key costs. Fuel-wise, at around 40-43 mpg and current diesel prices (approx. £1.60/litre), you're looking at roughly £0.17 per mile. Road tax (VED) for a 2021 model will be £570 per year (£180 standard rate plus the £390 premium car supplement). Insurance will be on the higher side due to the car's value and performance, likely ranging from £1,000 to £2,000+ annually depending on your personal circumstances. Servicing and maintenance, especially at a main dealer, can be expensive, so budgeting for that is crucial. Independent BMW specialists can offer a more cost-effective alternative.

## Key stats

- **Fuel Type**: Diesel
- **Horsepower**: 320 hp
- **Mpg**: 40-43 mpg
- **Reliability Score**: Good
- **Safety Rating**: 5 Stars (Euro NCAP 2019)

## Trim comparison

| Trim | Price new | Price used | Key features |
| --- | --- | --- | --- |
| 840i M Sport Gran Coupe | £78,000 | £31,000 | 3.0L TwinPower Turbo inline-six petrol engine (340hp); M Sport styling package; Adaptive M Suspension |
| 840d M Sport Gran Coupe | £81,000 | £32,500 | 3.0L TwinPower Turbo inline-six diesel engine (320hp); xDrive all-wheel drive system; M Sport styling package |
| M850i xDrive Gran Coupe | £103,000 | £43,000 | 4.4L TwinPower Turbo V8 petrol engine (530hp); xDrive all-wheel drive system; M Sport differential |

## Depreciation forecast

| Year | Estimated value | Retention |
| --- | --- | --- |
| 2026 | £31,990 | 0% |
| 2027 | £28,500 | 10.91% |
| 2028 | £25,000 | 21.85% |
| 2029 | £22,000 | 31.1% |
| 2030 | £19,500 | 39.04% |

Buying a luxury car like the 8 Series at 3-5 years old (like this 2021 model in 2026) is often the 'sweet spot' for depreciation. The steepest drop in value has already occurred during its first few years. While it will continue to depreciate, the rate of loss will be much slower than buying new. This means you get to enjoy a premium car at a significantly reduced price, and your future depreciation hit will be less severe.

Total value lost since new: 39.04%.

## Alternatives to consider

- [Mercedes-Benz CLS](https://autoscout.fyi/cars/mercedes-cls.md)
- Audi A7 Sportback
- [Porsche Panamera](https://autoscout.fyi/cars/porsche-panamera.md)

---

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