MERCEDES G (2021)
Running costs, common problems, and reliability data based on 1,202 real MOT tests in 2024.
MOT Pass Rate
96%
Total Tests (2024)
1,202
Avg Mileage
23,313 mi
Est. Annual Cost
£1,690
Is the 2021 MERCEDES G reliable?
Excellent reliability. Very few MOT failures. That's 14 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.
At 3 years old, 96% of MERCEDES Gs from 2021 passed their MOT first time in 2024. That's based on 1,202 tests across the UK. The average mileage at this age is 23,313 miles.
How does the 2021 MERCEDES G compare?
Mileage Analysis
The average 2021 MERCEDES G has 23,313 miles on the clock, which is in line with the expected 22,200 miles for a 3-year-old car, suggesting normal everyday use.
Best year to buy a MERCEDES G?
The most reliable year is the 2018 model with a 98% MOT pass rate, while the 2019 model has the lowest at 93%. The 2021 sits between the two at 96%.
How much does a 2021 MERCEDES G 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 G by Year
Checking a specific MERCEDES G?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2021 MERCEDES G
The 2021 MERCEDES G is a large car with a 2925cc diesel engine. 1,202 of these vehicles were MOT tested in 2024, making it a reasonably common sight on UK roads. It ranks in the top 15% of all 2021 cars for reliability.
With an average of 23,313 miles at 3 years old, MERCEDES G owners drive about as much as the UK average.
2021 MERCEDES G 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 G?
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 96% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
MERCEDES G Reliability Trend
The MERCEDES G has maintained consistent MOT pass rates across model years, varying by only 1 percentage points.
Buying a Used 2021 MERCEDES G
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 2018 model has the highest pass rate at 98%.
Alternatives to the 2021 MERCEDES G
The MERCEDES G is actually the most reliable option among similar diesel large cars from this era. Here are comparable diesel cars with similar engines:
- MERCEDES E (2019) 90% pass rate (-6%) from 41,000 tests
- FORD RANGER (2019) 87% pass rate (-9%) from 32,194 tests
- AUDI Q5 (2019) 93% pass rate (-3%) from 24,241 tests
- AUDI A5 (2019) 90% pass rate (-6%) from 22,290 tests