Mercedes GT (2021)
Estimated running costs and MOT pass rates from 94 MOT tests in 2024.
Annual Cost
£2,413
£201/month
MOT Pass Rate
100%
Excellent
Road Tax
£200
Standard rate/year
Est. Insurance
Grp 35-50
3982cc Petrol
Great Choice
100% pass rate, £2,413/year to run. 18 points above average.
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Annual Running Costs
~30 mpg
Standard rate (from April 2017)
Low estimate due to excellent reliability
Estimates based on 7,400 miles/year (UK average), petrol at 174.57p a litre (GOV.UK weekly average, week of 19 October 2026), GOV.UK road tax rates and repair likelihood from MOT data. Insurance not included. Cars registered from April 2017 pay the £200 standard rate, plus £440 a year for five years (from the second year) if they cost over £40,000 new (over £50,000 for electric cars).
Reliability Verdict
Excellent reliability. Very few MOT failures. That's 18 points above the average of 82% across all models in our data. It also outperforms the Mercedes brand average of 87%.
100% of MOT tests on Mercedes GTs from 2021 ended in a pass in 2024, when they were about 3 years old. That's based on 94 tests across the UK, retests included. The average mileage recorded at those tests was 15,449 miles.
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How Does It Compare?
Mileage Analysis
15,449
Average miles
22,200
Expected for age
The average 2021 Mercedes GT had 15,449 miles on the clock at its 2024 MOT, which is below the expected 22,200 miles for a 3-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?
Of the years with at least 100 tests, the 2018 model has the highest MOT pass rate at 98%, while the 2020 model has the lowest at 92%. The 2021 scores 100%. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.
Mercedes GT by Year
Similar Cars to Consider
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About the 2021 Mercedes GT
The 2021 Mercedes GT is a premium performance car. Our records list a 3982cc petrol engine, though engines vary between versions. 94 MOT tests were recorded on this model in 2024, making it a rare model on UK roads. It ranks in the top 1% of all 2021 models for MOT pass rate.
With an average of 15,449 miles recorded at its 2024 MOT tests, Mercedes GT owners tend to use this car less than the typical driver.
2021 Mercedes GT Fuel Costs
The 3982cc 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 £1,958 per year with petrol at 174.57p per litre (GOV.UK weekly average, week of 19 October 2026; based on 7,400 miles per year).
What does it cost to own a 2021 Mercedes GT?
Total estimated annual running cost is £2,413 (£201/month), broken down as £1,958 fuel, £200 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 100% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
Mercedes GT Reliability Trend
The Mercedes GT has maintained consistent MOT pass rates across model years, varying by only 1 percentage point.
Buying a Used 2021 Mercedes GT
At 5 years old, the Mercedes GT 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 2018 model has the highest pass rate at 98%. Note: with only 94 tests in our data, these figures should be treated as indicative rather than definitive.
Common Issues to Watch For
These are typical issues for cars of this age, fuel type and engine size, not faults recorded on this model's MOT tests. Use them as a checklist when you view one.
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 Mercedes GT stacks up against similar cars for estimated annual running costs, insurance group, and tax.
| Car | Pass Rate | Fuel/yr | Tax/yr | Est. Ins. Group | Total/yr |
|---|---|---|---|---|---|
| Mercedes GT(2021) | 100% | £1,958 | £200 | Grp 35-50 | £2,413 |
| Mercedes C(2019) | 91% | £1,958 | £200 | Grp 35-50 | £2,413same |
| Porsche Cayenne(2019) | 95% | £1,958 | £200 | Grp 35-50 | £2,413same |
| Porsche 911(2019) | 97% | £1,958 | £200 | Grp 35-50 | £2,413same |
| Audi A6(2020) | 94% | £1,958 | £200 | Grp 35-50 | £2,413same |
Estimates based on 7,400 miles/year, GOV.UK average pump prices for the week of 19 October 2026, GOV.UK road tax rates and MOT data. Insurance groups are our rough estimate from engine size, not official groups. Actual costs vary by driver, location, and usage.
Questions about the 2021 Mercedes GT
Is the 2021 Mercedes GT reliable?
Excellent reliability. Very few MOT failures. 100% of MOT tests on 2021 Mercedes GTs ended in a pass, from 94 tests (DVSA MOT data for tests in 2024, retests included). That's 18 points above the average of 82% across all models in the same data.
How much does a 2021 Mercedes GT cost to run?
Our estimate is £2,413 a year (£201 a month): £1,958 fuel, £200 road tax, £55 MOT and £200 predicted repairs, based on 7,400 miles a year. Insurance is not included.
What is the MOT pass rate for a 2021 Mercedes GT?
100% of 94 MOT tests on the 2021 Mercedes GT ended in a pass (DVSA MOT data for tests in 2024, retests included). That ranks it 10th of 3,336 models first registered in 2021 (top 1%).
Which year Mercedes GT has the best MOT pass rate?
Of the years with at least 100 tests, the 2018 Mercedes GT has the highest MOT pass rate at 98% and the 2020 the lowest at 92%. Newer cars usually pass more often simply because they are younger and have done fewer miles.
What is the average mileage for a 2021 Mercedes GT?
The average mileage recorded at MOT tests on the 2021 Mercedes GT is 15,449 miles, which is below the expected 22,200 miles for a 3-year-old car. This suggests lighter use than average, which generally means less wear on major components.
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
Mercedes C
2019 · 3982cc Petrol
Porsche Cayenne
2019 · 3996cc Petrol
Porsche 911
2019 · 3996cc Petrol
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