MERCEDES C 300 SPORT EDITION DE AUTO (2021)
Running costs, reliability data, and common problems from 189 real MOT tests.
Annual Cost
£1,927
£161/month
MOT Pass Rate
87%
Good
Road Tax
£195
Flat rate/year
Insurance
Grp 18-32
1950cc Petrol
Solid Option
87% pass rate, £1927/year to run. 5 points above average.
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Annual Running Costs
~36 mpg
Flat rate (post-2017)
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
Good reliability. Occasional issues but generally solid. That's close to the national average of 82%.
At 5 years old, 87% of MERCEDES C 300 SPORT EDITION DE AUTOs from 2021 passed their MOT first time in 2026. That's based on 189 tests across the UK. The average mileage at this age is 51,193 miles.
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How Does It Compare?
Mileage Analysis
51,193
Average miles
37,000
Expected for age
The average 2021 MERCEDES C 300 SPORT EDITION DE AUTO has 51,193 miles on the clock, which is above the expected 37,000 miles for a 5-year-old car. Higher-mileage cars often have more motorway miles, which is generally less harmful than stop-start urban driving.
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Best Year to Buy?
The most reliable year is the 2020 model with a 93% MOT pass rate, while the 2021 model has the lowest at 87%. Consider a different year if reliability is a priority.
MERCEDES C 300 SPORT EDITION DE AUTO by Year
Similar Cars to Consider
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About the 2021 MERCEDES C 300 SPORT EDITION DE AUTO
The 2021 MERCEDES C 300 SPORT EDITION DE AUTO is a family car with a 1950cc petrol engine. 189 of these vehicles were MOT tested in 2026, making it a rare model on UK roads. It sits in the bottom 88% of 2021 cars for MOT pass rates.
With an average of 51,193 miles at 5 years old, MERCEDES C 300 SPORT EDITION DE AUTO owners cover more miles than the average driver.
2021 MERCEDES C 300 SPORT EDITION DE AUTO Fuel Costs
The 1950cc 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 MERCEDES C 300 SPORT EDITION DE AUTO?
Total estimated annual running cost is £1,927 (£161/month), broken down as £1327 fuel, £195 road tax, £55 MOT, and £350 predicted repairs. Repair costs are moderate, reflecting the 87% pass rate. Keeping on top of servicing will help avoid surprises.
Buying a Used 2021 MERCEDES C 300 SPORT EDITION DE AUTO
At 5 years old, the MERCEDES C 300 SPORT EDITION DE AUTO offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost.
Common Issues to Watch For
Based on the 2021 MERCEDES C 300 SPORT EDITION DE AUTO's fuel type, age, and engine size, these are the most likely problem areas to check.
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 MERCEDES C 300 SPORT EDITION DE AUTO stacks up against similar cars for annual running costs, insurance, and tax.
| Car | Pass Rate | Fuel/yr | Tax/yr | Insurance | Total/yr |
|---|---|---|---|---|---|
| MERCEDES C 300 SPORT EDITION DE AUTO(2021) | 87% | £1327 | £195 | Grp 18-32 | £1927 |
| LAND ROVER DISCOVERY SPORT R-DYN SE D A(2020) | 90% | £1327 | £190 | Grp 18-32 | £1772-£155 |
| BMW 520D M SPORT MHEV AUTO(2021) | 89% | £1327 | £190 | Grp 18-32 | £1922-£5 |
| BMW 320D M SPORT MHEV AUTO(2021) | 91% | £1327 | £190 | Grp 18-32 | £1772-£155 |
| VOLVO XC90 R-DESIGN B5 MHEV AWD AUTO(2021) | 90% | £1327 | £190 | Grp 18-32 | £1772-£155 |
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 Mercedes Models
Explore other Mercedes cars or similar models in the same category.
MERCEDES A
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MERCEDES C
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MERCEDES A-CLASS
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LAND ROVER DISCOVERY SPORT R-DYN SE D A
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BMW 520D M SPORT MHEV AUTO
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BMW 320D M SPORT MHEV AUTO
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