MERCEDES GLS 400 AMG LN PREM + D 4MAT A (2021)
Running costs, common problems, and reliability data based on 297 real MOT tests in 2024.
MOT Pass Rate
90%
Total Tests (2024)
297
Avg Mileage
35,601 mi
Est. Annual Cost
£1,690
Is the 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A reliable?
Excellent reliability. Very few MOT failures. That's 8 points above the national average of 82%.
At 3 years old, 90% of MERCEDES GLS 400 AMG LN PREM + D 4MAT As from 2021 passed their MOT first time in 2024. That's based on 297 tests across the UK. The average mileage at this age is 35,601 miles.
How does the 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A compare?
Mileage Analysis
The average 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A has 35,601 miles on the clock, which is well above the expected 22,200 miles for a 3-year-old car. Check service history carefully, as high-mileage cars need consistent maintenance to stay reliable.
Best year to buy a MERCEDES GLS 400 AMG LN PREM + D 4MAT A?
The most reliable year is the 2019 model with a 99% MOT pass rate, while the 2021 model has the lowest at 90%. Consider a different year if reliability is a priority.
How much does a 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT 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 GLS 400 AMG LN PREM + D 4MAT A by Year
Checking a specific MERCEDES GLS 400 AMG LN PREM + D 4MAT A?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A
The 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A is a large car with a 2925cc diesel engine. 297 of these vehicles were MOT tested in 2024, making it a less common model in the UK market. It sits in the bottom 76% of 2021 cars for MOT pass rates.
With an average of 35,601 miles at 3 years old, MERCEDES GLS 400 AMG LN PREM + D 4MAT A owners cover more miles than the average driver. High-mileage examples should be checked carefully for wear on suspension, brakes, and drivetrain components.
2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A Fuel Costs
The 2925cc diesel engine is on the larger side, so fuel won't be this car's strong point. Expect around 40 mpg in mixed driving, which works out to roughly £1,245 per year at current diesel prices of 148p per litre (based on 7,400 miles per year).
What does it cost to own a 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A?
Total estimated annual running cost is £1,690 (£141/month), broken down as £1245 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 90% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
MERCEDES GLS 400 AMG LN PREM + D 4MAT A Reliability Trend
Older MERCEDES GLS 400 AMG LN PREM + D 4MAT As tend to have better MOT pass rates than newer ones, with an average decline of 8 percentage points across model years.
Buying a Used 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT 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.
Alternatives to the 2021 MERCEDES GLS 400 AMG LN PREM + D 4MAT A
If reliability is your priority, there's one similar car with a higher MOT pass rate. Here are comparable diesel cars with similar engines:
- MERCEDES E (2019) 90% pass rate (same) from 41,000 tests
- FORD RANGER (2019) 87% pass rate (-3%) from 32,194 tests
- AUDI Q5 (2019) 93% pass rate (+3%) from 24,241 tests
- AUDI A5 (2019) 90% pass rate (same) from 22,290 tests