Mercedes-Benz G-Class MOT pass rate & common failures
The Mercedes-Benz G-Class appears in 13,908 MOT tests spanning model years 1980–2024, and 89.5% of them passed. That is 2.3 percentage points better than large SUVs of a similar age, which fail at 12.9%. Its most common failure areas are lighting & signalling, tyres and brakes.
Best and worst G-Class years
Ranked across G-Class years with at least 1,000 tests. Older cars fail more simply because they are older — compare years close together in age before drawing conclusions.
What the MOT record shows
Build year matters more than the headline suggests: 2020 cars pass 93.2% of the time while 2017 cars manage 88.0%, a 5.2-point spread.
No single area dominates — lighting & signalling (4.4%) and tyres (3.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, registration plates and brake pads — headlamp aim alone was recorded 401 times.
A 150k+ example is materially riskier than a 0-30k one: 21.1% versus 6.9%.
The petrol cars hold up better: 9.3% fail against 12.3% for diesel, a 3.0-point gap across 13,897 tests.
Tyres is the most common advisory, noted on 12.2% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 11.9% in 2021 to 9.9% in 2025, as the worst-kept examples leave the fleet.
How it compares
By model year
Every G-Class model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 1989 | 37 | 75.7% | 24.3% | Suspension |
| 1990 | 70 | 75.7% | 24.3% | Lighting & signalling |
| 1991 | 42 | 83.3% | 16.7% | Visibility |
| 1992 | 31 | 83.9% | 16.1% | Lighting & signalling |
| 1993 | 40 | 82.5% | 17.5% | Steering |
| 1998 | 32 | 78.1% | 21.9% | Lighting & signalling |
| 1999 | 86 | 82.6% | 17.4% | Lighting & signalling |
| 2000 | 95 | 89.5% | 10.5% | Lighting & signalling |
| 2001 | 73 | 84.9% | 15.1% | Lighting & signalling |
| 2002 | 78 | 79.5% | 20.5% | Lighting & signalling |
| 2003 | 47 | 91.5% | 8.5% | Body, structure & corrosion |
| 2004 | 49 | 85.7% | 14.3% | Lighting & signalling |
| 2005 | 55 | 92.7% | 7.3% | Lighting & signalling |
| 2006 | 74 | 75.7% | 24.3% | Lighting & signalling |
| 2007 | 74 | 82.4% | 17.6% | Lighting & signalling |
| 2008 | 68 | 89.7% | 10.3% | Lighting & signalling |
| 2009 | 62 | 85.5% | 14.5% | Lighting & signalling |
| 2010 | 161 | 80.1% | 19.9% | Lighting & signalling |
| 2011 | 521 | 84.8% | 15.2% | Lighting & signalling |
| 2012 | 595 | 85.5% | 14.4% | Lighting & signalling |
| 2013 | 645 | 89.0% | 11.0% | Lighting & signalling |
| 2014 | 685 | 87.6% | 12.4% | Lighting & signalling |
| 2015 | 892 | 86.0% | 14.0% | Lighting & signalling |
| 2016 | 976 | 88.0% | 12.0% | Lighting & signalling |
| 2017 | 1,296 | 88.0% | 12.0% | Lighting & signalling |
| 2018 | 1,498 | 91.3% | 8.7% | Lighting & signalling |
| 2019 | 2,424 | 93.0% | 7.0% | Tyres |
| 2020 | 1,331 | 93.2% | 6.8% | Tyres |
| 2021 | 1,203 | 92.9% | 7.1% | Tyres |
| 2022 | 497 | 93.8% | 6.2% | Tyres |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 4.4% | 612 |
| 2 | Tyres | 3.1% | 432 |
| 3 | Brakes | 2.5% | 350 |
| 4 | Visibility | 1.5% | 210 |
| 5 | Emissions & environmental | 1.5% | 209 |
| 6 | Suspension | 1.4% | 197 |
| 7 | Steering | 1.3% | 174 |
| 8 | Other defects | 1.1% | 154 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 401 |
| 2 | Registration plates | 274 |
| 3 | Brake pads | 166 |
| 4 | Wipers | 157 |
| 5 | Coil spring | 142 |
| 6 | Individual direction indicators | 135 |
| 7 | Tread depth | 121 |
| 8 | Track rod end | 120 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 12.2% | 1,692 |
| 2 | Brakes | 10.7% | 1,491 |
| 3 | Emissions & environmental | 4.6% | 641 |
| 4 | Other defects | 4.3% | 603 |
| 5 | Suspension | 4.2% | 586 |
| 6 | Steering | 3.7% | 514 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 5,057 | 6.9% |
| 30-60k | 5,455 | 11.2% |
| 60-90k | 2,033 | 13.0% |
| 90-120k | 815 | 16.7% |
| 120-150k | 313 | 16.6% |
| 150k+ | 218 | 21.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 8,405 | 9.3% |
| Diesel | 5,492 | 12.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,713 | 11.9% |
| 2022 | 2,344 | 10.9% |
| 2023 | 2,748 | 10.0% |
| 2024 | 3,280 | 10.7% |
| 2025 | 3,823 | 9.9% |
What to check before buying a Mercedes-Benz G-Class
- Lighting & signalling (4.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (3.1% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Brakes (2.5% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
What is the MOT pass rate for the Mercedes-Benz G-Class?
89.5% of the 13,908 Mercedes-Benz G-Class MOT tests in this dataset passed, a 10.5% fail rate, across model years 1980–2024.
What does the Mercedes-Benz G-Class most often fail its MOT on?
Lighting & signalling, recorded in 4.4% of tests, then tyres (3.1%).
Which G-Class years are best and worst for MOT results?
2020 has the best pass rate at 93.2% and 2017 the weakest at 88.0%, from 1,331 and 1,296 tests respectively.
How much does mileage affect G-Class MOT results?
Fail rates run at 6.9% for cars in the 0-30k band and 21.1% for 150k+, a 14.2-point difference.
Is the petrol or diesel G-Class more reliable at MOT time?
On MOT-testable defects the petrol fails 9.3% of the time against 12.3% for the diesel. This covers testable items only, not engine or gearbox reliability.
Methodology & source. Based on 13,908 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.