2021 BMW 4 Series 2.0 420i M Sport

Overview

• Make: BMW
• Model: 4 Series
• Trim: M Sport
• Version: 2.0 420i M Sport Auto RWD Euro 6 (s/s) 2dr (181 bhp)
• Year: 2021
• Mileage: 97,313 miles
• Fuel: Petrol
• Body: Convertible, 2 doors, 4 seats
• Engine: 2.0 litres, 181 bhp
• Gearbox: Automatic
• Drive: Rear-wheel drive
• Colour: Blue
• CO2: 160 g/km
• Emissions standard: Euro 6, ULEZ compliant

About this car

This 2021 BMW 4 Series M Sport is advertised with 97,313 miles on the clock. The AskCar estimate for this car is £16,559. It is priced at £18,990, which is £2,431 above that estimate. To work out the AskCar estimate, we analyse UK dealer adverts for 1,814 BMW 4 Series cars across different ages and specifications. Since we first spotted the advert 85 days ago, the asking price has dropped by £3,000. The latest MOT recorded 97,921 miles, above the advertised mileage. Check this with the dealer. It is for sale at CS Autos Prestige Cars in Runnymede. How to contact the dealer and its opening hours are on this AskCar page.

Stock data as of 4 November 2026.

How we estimate prices and check cars

Price

Above the going rate: £2,431 (14%) over the AskCar estimate of £16,559.

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 1,814 priced BMW 4 Series adverts across different ages and specifications, as of 4 November 2026.

A 2021 BMW 4 Series with the 2.0 petrol engine is typically advertised at £24,000: the median of the 144 for sale on AskCar, as of 4 November 2026.

Time on sale

This 2021 BMW 4 Series has been on sale for at least 85 days.

Price history

AskCar first saw this advert on 11 August 2026 at £21,990. Its asking price is now £18,990, £3,000 less. The latest price cut was seen on 16 October 2026.

Price changes recorded:

• 11 August 2026: £21,990
• 16 October 2026: £18,990

Mileage and MOT

It has had one MOT, on 14 April 2026, and passed.

There were no advisories at the latest test.

Mileage at that test: 97,921 miles. The advert says 97,313 miles, fewer than the MOT record, so ask the dealer which is right.

Advertised mileage is about 53,200 miles higher 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 £20,999 to £33,950, as of 4 November 2026.

The 3 closest to this car in mileage:

• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, black. Mileage: 72,748 miles. Price: £20,999, £2,009 more than this car. Dealer: Pro-Division Car Sales in Stirling. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-7396e5991916
• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, black. Mileage: 68,323 miles. Price: £21,000, £2,010 more than this car. Dealer: Grange. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-1bfff9575fa2
• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, black. Mileage: 65,000 miles. Price: £22,988, £3,998 more than this car. Dealer: West Kent Motor Group Online in Sevenoaks. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-dfed66a66f81

• The nearest: 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white, 7 miles from this car. Mileage: 33,078 miles. Price: £27,750, £8,760 more than this car. Dealer: Vines of Guildford BMW in Guildford. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-e16967b0feee