BMW 420I M SPORT AUTO (2021)
Running costs, common problems, and reliability data based on 6,945 real MOT tests in 2024.
MOT Pass Rate
93%
Total Tests (2024)
6,945
Avg Mileage
23,926 mi
Est. Annual Cost
£1,772
Is the 2021 BMW 420I M SPORT AUTO reliable?
Excellent reliability. Very few MOT failures. That's 11 points above the national average of 82%. It also outperforms the BMW brand average of 88%.
At 3 years old, 93% of BMW 420I M SPORT AUTOs from 2021 passed their MOT first time in 2024. That's based on 6,945 tests across the UK. The average mileage at this age is 23,926 miles.
How does the 2021 BMW 420I M SPORT AUTO compare?
Mileage Analysis
The average 2021 BMW 420I M SPORT AUTO has 23,926 miles on the clock, which is in line with the expected 22,200 miles for a 3-year-old car, suggesting normal everyday use.
Best year to buy a BMW 420I M SPORT AUTO?
The most reliable year is the 2022 model with a 96% MOT pass rate, while the 2021 model has the lowest at 93%. Consider a different year if reliability is a priority.
How much does a 2021 BMW 420I M SPORT AUTO cost to run?
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT pass rate data. Insurance not included.
BMW 420I M SPORT AUTO by Year
Checking a specific BMW 420I M SPORT AUTO?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2021 BMW 420I M SPORT AUTO
The 2021 BMW 420I M SPORT AUTO is a premium with a 1998cc petrol engine. 6,945 of these vehicles were MOT tested in 2024, making it a reasonably common sight on UK roads. Among all cars from 2021, the average MOT pass rate is 92%, and this model beats that benchmark.
With an average of 23,926 miles at 3 years old, BMW 420I M SPORT AUTO owners drive about as much as the UK average.
2021 BMW 420I M SPORT AUTO Fuel Costs
The 1998cc petrol engine offers a reasonable balance between performance and economy. Expect around 36 mpg in mixed driving, which works out to roughly £1,327 per year at current petrol prices of 142p per litre (based on 7,400 miles per year).
What does it cost to own a 2021 BMW 420I M SPORT AUTO?
Total estimated annual running cost is £1,772 (£148/month), broken down as £1327 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 93% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
BMW 420I M SPORT AUTO Reliability Trend
The BMW 420I M SPORT AUTO has maintained consistent MOT pass rates across model years, varying by only 1 percentage points.
Buying a Used 2021 BMW 420I M SPORT AUTO
At 3 years old, this is still relatively fresh. You may find examples with remaining manufacturer warranty. Depreciation is slowing but hasn't bottomed out yet. With 6,945 MOT tests in our data, there's strong statistical confidence in these figures.
Alternatives to the 2021 BMW 420I M SPORT AUTO
The BMW 420I M SPORT AUTO is actually the most reliable option among similar petrol premiums from this era. Here are comparable petrol cars with similar engines:
- VOLKSWAGEN GOLF (2019) 92% pass rate (-1%) from 89,653 tests
- NISSAN QASHQAI (2020) 93% pass rate (same) from 52,321 tests
- MINI COOPER (2019) 92% pass rate (-1%) from 52,140 tests
- HYUNDAI TUCSON (2019) 90% pass rate (-3%) from 42,920 tests