BMW 340I (2021)
Running costs, reliability data, and common problems from 49 real MOT tests.
Annual Cost
£2,042
£170/month
MOT Pass Rate
96%
Excellent
Road Tax
£195
Flat rate/year
Insurance
Grp 30-42
2998cc Petrol
Great Choice
96% pass rate, £2042/year to run. 14 points above average.
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Annual Running Costs
~30 mpg
Flat rate (post-2017)
Low estimate due to excellent reliability
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT data. Insurance not included.
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Reliability Verdict
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 5 years old, 96% of BMW 340Is from 2021 passed their MOT first time in 2026. That's based on 49 tests across the UK. The average mileage at this age is 21,253 miles.
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How Does It Compare?
Mileage Analysis
21,253
Average miles
37,000
Expected for age
The average 2021 BMW 340I has 21,253 miles on the clock, which is below the expected 37,000 miles for a 5-year-old car. This suggests lighter use than average, which generally means less wear on major components.
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Best Year to Buy?
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%.
BMW 340I by Year
Similar Cars to Consider
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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 2026, 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 5 years old, BMW 340I owners tend to use this car less than the typical driver.
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 £2,042 (£170/month), broken down as £1592 fuel, £195 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 5 years old, the BMW 340I offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost. 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.
Common Issues to Watch For
Based on the 2021 BMW 340I's fuel type, age, and engine size, these are the most likely problem areas to check.
Oil Consumption
Low riskLarger petrol engines can develop higher oil consumption as they age. Check the oil level and look for blue smoke from the exhaust.
Service History
Low riskAlways request a full service history. Regular servicing is the single best indicator of how well a car has been maintained, regardless of mileage.
Running Costs Compared
How the 2021 BMW 340I stacks up against similar cars for annual running costs, insurance, and tax.
| Car | Pass Rate | Fuel/yr | Tax/yr | Insurance | Total/yr |
|---|---|---|---|---|---|
| BMW 340I(2021) | 96% | £1592 | £195 | Grp 30-42 | £2042 |
| BMW 5 SERIES(2019) | 92% | £1592 | £190 | Grp 30-42 | £2037-£5 |
| BMW X3(2019) | 92% | £1592 | £190 | Grp 30-42 | £2037-£5 |
| MERCEDES GLC(2019) | 93% | £1592 | £190 | Grp 30-42 | £2037-£5 |
| BMW X5(2019) | 92% | £1592 | £190 | Grp 30-42 | £2037-£5 |
Estimates based on 7,400 miles/year, current fuel prices, and MOT data. Insurance groups are indicative. Actual costs vary by driver, location, and usage.
Related Bmw Models
Explore other Bmw cars or similar models in the same category.
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BMW 5 SERIES
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BMW 5 SERIES
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MERCEDES GLC
2019 · 2996cc Petrol
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