MERCEDES SL 400 GRAND EDITION PREMIUM A (2021)
Running costs, common problems, and reliability data based on 41 real MOT tests in 2024.
MOT Pass Rate
100%
Total Tests (2024)
41
Avg Mileage
13,184 mi
Est. Annual Cost
£2,037
Is the 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A reliable?
Excellent reliability. Very few MOT failures. That's 18 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.
At 3 years old, 100% of MERCEDES SL 400 GRAND EDITION PREMIUM As from 2021 passed their MOT first time in 2024. That's based on 41 tests across the UK. The average mileage at this age is 13,184 miles.
How does the 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A compare?
Mileage Analysis
The average 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A has 13,184 miles on the clock, 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.
Best year to buy a MERCEDES SL 400 GRAND EDITION PREMIUM A?
The most reliable year is the 2020 model with a 97% MOT pass rate, while the 2019 model has the lowest at 97%. The 2021 sits between the two at 100%.
How much does a 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A 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.
MERCEDES SL 400 GRAND EDITION PREMIUM A by Year
Checking a specific MERCEDES SL 400 GRAND EDITION PREMIUM A?
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About the 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A
The 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A is a large car with a 2996cc petrol engine. 41 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. It ranks in the top 2% of all 2021 cars for reliability.
With an average of 13,184 miles at 3 years old, MERCEDES SL 400 GRAND EDITION PREMIUM A owners tend to use this car less than the typical driver.
2021 MERCEDES SL 400 GRAND EDITION PREMIUM A Fuel Costs
The 2996cc 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 MERCEDES SL 400 GRAND EDITION PREMIUM A?
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 100% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
Buying a Used 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A
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 2020 model has the highest pass rate at 97%. Note: with only 41 tests in our data, these figures should be treated as indicative rather than definitive.
Alternatives to the 2021 MERCEDES SL 400 GRAND EDITION PREMIUM A
The MERCEDES SL 400 GRAND EDITION PREMIUM A is actually the most reliable option among similar petrol large cars from this era. Here are comparable petrol cars with similar engines:
- BMW 5 SERIES (2019) 92% pass rate (-8%) from 33,766 tests
- BMW X3 (2019) 92% pass rate (-8%) from 32,937 tests
- MERCEDES GLC (2019) 93% pass rate (-7%) from 30,341 tests
- BMW X5 (2019) 92% pass rate (-8%) from 23,506 tests