2021 BMW 4 Series 2.0 420i M Sport

Overview

• Make: BMW
• Model: 4 Series
• Trim: M Sport
• Version: 2.0 420i M Sport [Tech/Pro Pack] Auto RWD Euro 6 2dr Step (181 bhp)
• Year: 2021
• Mileage: 40,658 miles
• Fuel: Petrol
• Body: Convertible, 2 doors, 4 seats
• Engine: 2.0 litres, 181 bhp
• Gearbox: Automatic
• Drive: Rear-wheel drive
• Colour: Black
• CO2: 154 g/km
• Emissions standard: Euro 6, ULEZ compliant

About this car

This 2021 BMW 4 Series M Sport has covered 40,658 miles, around 3,400 fewer miles than is typical for its age. The AskCar estimate for this car is £25,116. It is priced at £26,500, which is £1,384 above that estimate. The AskCar estimate draws on 1,833 BMW 4 Series adverts across the UK, adjusting for age, mileage, trim, engine and other specifications. We first saw this car advertised 21 days ago. Its asking price has since fallen by £500. We checked its advertised mileage against the government's MOT record, and they match. The seller is Sytner High Wycombe BMW, based in High Wycombe. How to contact the dealer and its opening hours are on this AskCar page.

Stock data as of 5 November 2026.

How we estimate prices and check cars

Price

Fair price: £1,384 (5%) over the AskCar estimate of £25,116.

The AskCar estimate is our expected asking price for this car. It uses UK dealer asking prices, accounting for make, model, trim, version, age, mileage, fuel, gearbox, body type, driven wheels, engine size and power. It is an advertised price, not a confirmed sale price.

It draws on 1,833 priced BMW 4 Series adverts across different ages and specifications, as of 5 November 2026.

A 2021 BMW 4 Series with the 2.0 petrol engine is typically advertised at £24,000: the median of the 149 for sale on AskCar, as of 5 November 2026.

Time on sale

This 2021 BMW 4 Series has been on sale for at least 21 days.

Price history

AskCar first saw this advert on 15 October 2026 at £27,000. Its asking price is now £26,500, £500 less. The latest price cut was seen on 2 November 2026.

Price changes recorded:

• 15 October 2026: £27,000
• 2 November 2026: £26,500

Mileage and MOT

MOT, from the government's MOT records (DVSA, the Driver and Vehicle Standards Agency), as of 5 November 2026: valid until 2 October 2027.

It has had 5 MOTs. The latest, on 3 October 2026, passed.

Advisories at the latest test: nearside front inner tyre worn close to legal limit/worn on edge.

Mileage at that test: 40,518 miles, which matches the advertised 40,658 miles.

Advertised mileage is about 3,400 miles lower than the median mileage of a 2021 BMW 4 Series on AskCar.

Similar cars

26 other 2021 BMW 4 Series M Sport 2.0 petrol automatic convertibles are for sale at UK dealers, from £18,990 to £33,950, as of 5 November 2026.

The 3 closest to this car in mileage:

• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, green. Mileage: 41,580 miles. Price: £25,895, £605 less than this car. Dealer: Century Cars in Turners Hill. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-8fafe0e55cc8
• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white. Mileage: 41,900 miles. Price: £26,995, £495 more than this car. Dealer: Car Monkey in Rawtenstall. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-e74a6040c3cb
• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, black. Mileage: 42,000 miles. Price: £24,950, £1,550 less than this car. Dealer: Sovereign Trading in Eastbourne. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-717fbcb098d6

• The nearest: 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white, 13 miles from this car. Mileage: 37,652 miles. Price: £22,550, £3,950 less than this car. Dealer: Car Planet Watford in Watford. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-51fe39d2b593