BMW 340I (2021)
Running costs, common problems, and reliability data based on 49 real MOT tests in 2024.
MOT Pass Rate
96%
Total Tests (2024)
49
Avg Mileage
21,253 mi
Est. Annual Cost
£2,037
Is the 2021 BMW 340I reliable?
Excellent reliability. Very few MOT failures. That's 14 points above the national average of 82%. It also outperforms the BMW brand average of 88%.
At 3 years old, 96% of BMW 340Is from 2021 passed their MOT first time in 2024. That's based on 49 tests across the UK. The average mileage at this age is 21,253 miles.
How does the 2021 BMW 340I compare?
Mileage Analysis
The average 2021 BMW 340I has 21,253 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 340I?
The most reliable year is the 2016 model with a 95% MOT pass rate, while the 2019 model has the lowest at 90%. The 2021 sits between the two at 96%.
How much does a 2021 BMW 340I 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 340I by Year
Checking a specific BMW 340I?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2021 BMW 340I
The 2021 BMW 340I is a premium performance with a 2998cc petrol engine. 49 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. It ranks in the top 21% of all 2021 cars for reliability.
With an average of 21,253 miles at 3 years old, BMW 340I owners drive about as much as the UK average.
2021 BMW 340I Fuel Costs
The 2998cc petrol engine is on the larger side, so fuel won't be this car's strong point. Expect around 30 mpg in mixed driving, which works out to roughly £1,592 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 340I?
Total estimated annual running cost is £2,037 (£170/month), broken down as £1592 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 96% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
BMW 340I Reliability Trend
The BMW 340I has maintained consistent MOT pass rates across model years, varying by only 2 percentage points.
Buying a Used 2021 BMW 340I
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. If you're flexible on year, the 2016 model has the highest pass rate at 95%. Note: with only 49 tests in our data, these figures should be treated as indicative rather than definitive.
Alternatives to the 2021 BMW 340I
The BMW 340I is actually the most reliable option among similar petrol premium performances from this era. Here are comparable petrol cars with similar engines:
- BMW 5 SERIES (2019) 92% pass rate (-4%) from 33,766 tests
- BMW X3 (2019) 92% pass rate (-4%) from 32,937 tests
- MERCEDES GLC (2019) 93% pass rate (-3%) from 30,341 tests
- BMW X5 (2019) 92% pass rate (-4%) from 23,506 tests