2021 BMW 4 Series 2.0 420d MHT M Sport

Overview

• Make: BMW
• Model: 4 Series
• Trim: M Sport
• Version: 2.0 420d MHT M Sport Auto RWD Euro 6 (s/s) 2dr (187 bhp)
• Year: 2021
• Mileage: 20,000 miles
• Fuel: Diesel, mild hybrid
• Body: Convertible, 2 doors, 4 seats
• Engine: 2.0 litres, 187 bhp
• Gearbox: Automatic
• Drive: Rear-wheel drive
• Colour: Blue
• CO2: 129 g/km
• Emissions standard: Euro 6, ULEZ compliant

About this car

This 2021 BMW 4 Series M Sport is advertised with 20,000 miles, approximately 24,300 below the typical mileage for its age. The dealer is asking £21,990, which is £4,848 below the AskCar estimate of £26,838. To work out the AskCar estimate, we analyse UK dealer adverts for 1,822 BMW 4 Series cars across different ages and specifications. We have tracked this advert for 1 day. According to the government's MOT record, its advertised mileage is consistent with the latest test. The seller is Quality Part Ex Southall, based in Southall. How to contact the dealer and its opening hours are on this AskCar page.

Stock data as of 12 November 2026.

How we estimate prices and check cars

Price

Good value: £4,848 (18%) under the AskCar estimate of £26,838.

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 1,822 priced BMW 4 Series adverts across different ages and specifications, as of 12 November 2026.

A 2021 BMW 4 Series with the 2.0 diesel engine is typically advertised at £23,700: the median of the 146 for sale on AskCar, as of 12 November 2026.

Time on sale

AskCar first saw this 2021 BMW 4 Series advertised 1 day ago. About 4 in 10 of 2021 BMW 4 Series cars are gone from sale within a month of being advertised: 116 of the 275 first advertised between 13 July 2026 and 9 October 2026.

Price history

AskCar first saw this advert on 11 November 2026 at £21,990. Its asking price has not changed.

Mileage and MOT

MOT, from the government's MOT records (DVSA, the Driver and Vehicle Standards Agency), as of 12 November 2026: valid until 21 April 2027.

It has had 3 MOTs. The latest, on 15 April 2026, passed.

There were no advisories at the latest test.

Mileage at that test: 20,093 miles, which matches the advertised 20,000 miles.

Advertised mileage is about 24,300 miles lower than the median mileage of a 2021 BMW 4 Series on AskCar.

Similar cars

7 other 2021 BMW 4 Series M Sport 2.0 diesel automatic convertibles are for sale at UK dealers, from £21,999 to £28,745, as of 12 November 2026.

The 3 closest to this car in mileage:

• 2021 BMW 4 Series M Sport, 2.0 diesel convertible, blue. Mileage: 9,654 miles. Price: £28,745, £6,755 more than this car. Dealer: Group 1 Borehamwood BMW in Borehamwood. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-ae16c0438fca
• 2021 BMW 4 Series M Sport, 2.0 diesel convertible, white. Mileage: 34,868 miles. Price: £22,795, £805 more than this car. Dealer: Williams Bmw Rochdale in Rochdale. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-d1c51114b60d
• 2021 BMW 4 Series M Sport, 2.0 diesel convertible, white. Mileage: 37,500 miles. Price: £23,600, £1,610 more than this car. Dealer: Colin Ludwell Cars in Bristol. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-9227194baa3c