MERCEDES C 300 AMG LINE EDITION AUTO (2020)
Running costs, reliability data, and common problems from 98 real MOT tests.
Annual Cost
£1,777
£148/month
MOT Pass Rate
92%
Excellent
Road Tax
£195
Flat rate/year
Insurance
Grp 18-32
1991cc Petrol
Great Choice
92% pass rate, £1777/year to run. 10 points above average.
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Annual Running Costs
~36 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 10 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.
At 6 years old, 92% of MERCEDES C 300 AMG LINE EDITION AUTOs from 2020 passed their MOT first time in 2026. That's based on 98 tests across the UK. The average mileage at this age is 46,412 miles.
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How Does It Compare?
Mileage Analysis
46,412
Average miles
44,400
Expected for age
The average 2020 MERCEDES C 300 AMG LINE EDITION AUTO has 46,412 miles on the clock, which is in line with the expected 44,400 miles for a 6-year-old car, suggesting normal everyday use.
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About the 2020 MERCEDES C 300 AMG LINE EDITION AUTO
The 2020 MERCEDES C 300 AMG LINE EDITION AUTO is a family car with a 1991cc petrol engine. 98 of these vehicles were MOT tested in 2026, making it a rare model on UK roads. Among all cars from 2020, the average MOT pass rate is 92%, and this model falls short of that benchmark.
With an average of 46,412 miles at 6 years old, MERCEDES C 300 AMG LINE EDITION AUTO owners drive about as much as the UK average.
2020 MERCEDES C 300 AMG LINE EDITION AUTO Fuel Costs
The 1991cc 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 2020 MERCEDES C 300 AMG LINE EDITION AUTO?
Total estimated annual running cost is £1,777 (£148/month), broken down as £1327 fuel, £195 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 92% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
Buying a Used 2020 MERCEDES C 300 AMG LINE EDITION AUTO
At 6 years old, the MERCEDES C 300 AMG LINE EDITION AUTO offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost. Note: with only 98 tests in our data, these figures should be treated as indicative rather than definitive.
Common Issues to Watch For
Based on the 2020 MERCEDES C 300 AMG LINE EDITION AUTO's fuel type, age, and engine size, these are the most likely problem areas to check.
Timing Chain / Belt
Watch outAt 6 years old, check whether the timing belt has been replaced (typically due every 5-7 years or 60,000-100,000 miles). A snapped belt can destroy the engine.
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 2020 MERCEDES C 300 AMG LINE EDITION 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 AMG LINE EDITION AUTO(2020) | 92% | £1327 | £195 | Grp 18-32 | £1777 |
| VOLKSWAGEN GOLF(2019) | 92% | £1137 | £190 | Grp 12-25 | £1582-£195 |
| FORD KUGA(2018) | 90% | £1137 | £190 | Grp 12-25 | £1582-£195 |
| MINI COOPER(2018) | 92% | £1137 | £190 | Grp 12-25 | £1582-£195 |
| NISSAN QASHQAI(2020) | 93% | £1137 | £190 | Grp 12-25 | £1582-£195 |
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
2019 · 1461cc Diesel
MERCEDES C
2017 · 1991cc Hybrid
MERCEDES A-CLASS
2017 · 1461cc Diesel
VOLKSWAGEN GOLF
2019 · 1498cc Petrol
FORD KUGA
2018 · 1499cc Petrol
MINI COOPER
2018 · 1499cc Petrol
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