MERCEDES G-CLASS (2020)
Running costs, common problems, and reliability data based on 66 real MOT tests in 2024.
MOT Pass Rate
98%
Total Tests (2024)
66
Avg Mileage
32,570 mi
Est. Annual Cost
£2,037
Is the 2020 MERCEDES G-CLASS reliable?
Excellent reliability. Very few MOT failures. That's 16 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.
At 4 years old, 98% of MERCEDES G-CLASSs from 2020 passed their MOT first time in 2024. That's based on 66 tests across the UK. The average mileage at this age is 32,570 miles.
How does the 2020 MERCEDES G-CLASS compare?
Mileage Analysis
The average 2020 MERCEDES G-CLASS has 32,570 miles on the clock, which is in line with the expected 29,600 miles for a 4-year-old car, suggesting normal everyday use.
How much does a 2020 MERCEDES G-CLASS 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-CLASS by Year
| Year | Pass Rate | Tests | Avg Mileage |
|---|---|---|---|
| 2021 | 78% | 65 | 30,190 mi |
| 2020 | 98% | 66 | 32,570 mi |
| 2019 | 96% | 319 | 41,698 mi |
| 2018 | 94% | 807 | 39,199 mi |
| 2017 | 86% | 691 | 43,730 mi |
| 2016 | 94% | 604 | 58,012 mi |
| 2015 | 88% | 591 | 48,991 mi |
| 2014 | 92% | 362 | 54,969 mi |
| 2013 | 94% | 449 | 69,675 mi |
| 2012 | 90% | 221 | 76,209 mi |
| 2011 | 96% | 92 | 70,666 mi |
| 2010 | 73% | 33 | 78,145 mi |
| 2007 | 100% | 35 | 103,461 mi |
| 2001 | 60% | 42 | 93,234 mi |
| 1999 | 82% | 44 | 113,541 mi |
Checking a specific MERCEDES G-CLASS?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2020 MERCEDES G-CLASS
The 2020 MERCEDES G-CLASS is a performance with a 3982cc petrol engine. 66 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. It ranks in the top 6% of all 2020 cars for reliability.
With an average of 32,570 miles at 4 years old, MERCEDES G-CLASS owners drive about as much as the UK average.
2020 MERCEDES G-CLASS 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 £1,592 per year at current petrol prices of 142p per litre (based on 7,400 miles per year).
What does it cost to own a 2020 MERCEDES G-CLASS?
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 98% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
MERCEDES G-CLASS Reliability Trend
The MERCEDES G-CLASS has maintained consistent MOT pass rates across model years, varying by only 1 percentage points.
Buying a Used 2020 MERCEDES G-CLASS
At 4 years old, the MERCEDES G-CLASS 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 66 tests in our data, these figures should be treated as indicative rather than definitive.
Alternatives to the 2020 MERCEDES G-CLASS
The MERCEDES G-CLASS is actually the most reliable option among similar petrol performances from this era. Here are comparable petrol cars with similar engines:
- MERCEDES C (2019) 91% pass rate (-7%) from 52,838 tests
- PORSCHE CAYENNE (2019) 95% pass rate (-3%) from 9,063 tests
- PORSCHE 911 (2018) 96% pass rate (-2%) from 7,623 tests
- AUDI A6 (2020) 94% pass rate (-4%) from 3,470 tests