1991 Mercedes 420 — MOT History by Age
How cars manufactured in 1991 perform at MOT as they age
35 years
Current Age
61.3%
Latest Pass Rate
31
Total Tests (All Years)
121,951 mi
Avg Mileage (Latest)
Data from official DVSA MOT testing records
Compared to Average at Age 18
This car: 61.3%
Average: 54.3%
✅ 7.0% above average (8383 models compared)
How This Car Ages
📉
Insufficient data for this analysis
Pass Rate Trend
📊
Insufficient data for this analysis
Year-by-Year MOT Results
2009High Fail Rate
61.3%
Age (yrs) 18Tests 31Avg Mileage 121,951Top Failure Exhaust, Fuel and Emissions — 22.6%
Common MOT Failures
Top failure categories across all test years for 1991 Mercedes 420, with age trends.
Exhaust, Fuel and Emissions
22.6%
— Consistent
Brakes
19.4%
— Consistent
Suspension
16.1%
— Consistent
Tyres
12.9%
— Consistent
Lamps, Reflectors and Electrical Equipment
9.7%
— Consistent
How Failures Change With Age
Comparing failure rates between the youngest and oldest test years.
| Category | At Youngest | At Oldest | Change | Trend |
|---|---|---|---|---|
| Exhaust, Fuel and Emissions | 22.6% (18 yrs) | 22.6% (18 yrs) | 0.0%
| ⚪ — |
| Brakes | 19.4% (18 yrs) | 19.4% (18 yrs) | 0.0%
| ⚪ — |
| Suspension | 16.1% (18 yrs) | 16.1% (18 yrs) | 0.0%
| ⚪ — |
| Tyres | 12.9% (18 yrs) | 12.9% (18 yrs) | 0.0%
| ⚪ — |
| Lamps, Reflectors and Electrical Equipment | 9.7% (18 yrs) | 9.7% (18 yrs) | 0.0%
| ⚪ — |
Other Manufacture Years
Looking for the best year to buy? See the full comparison on the Mercedes 420 page →
About This Data
This page shows how Mercedes 420 cars manufactured in 1991 perform at MOT as they age. Data spans from 2009 to 2009, covering 31 tests. Pass rates naturally decline with age as components wear.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.