Mercedes 811d MOT Pass Rate
Overall pass rate across all manufacture years, based on 461 real MOT test results. Failure rate: 39.5%.
Data from official DVSA MOT testing records
Mercedes 811d MOT Reliability Overview
The Mercedes 811d is a rare vehicle in the UK, with 461 MOT test results recorded in our database spanning 7 manufacture years. It has an overall MOT pass rate of 60.5% and a failure rate of 39.5%, which is around the UK average of approximately 37%.
Based on this data, the Mercedes 811d earns a "Average" reliability rating. The average Mercedes 811d presents for MOT with approximately 239,487 miles on the clock. Manufacture year matters: 1992 models achieve the highest pass rate at 86.3%, while 1988 models have the lowest at 55.6%. This 30.7 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Mercedes 811d is Brakes, affecting 51.4% of all tests. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. The second most common issue is Suspension at 27.5%. Steering rounds out the top three at 23.9%. Together, these top 3 failure categories account for a significant portion of all MOT failures for this model.
Top failures across all manufacture years combined. Individual year pages may show different top failures.
What Fails Most
Pass Rate by Manufacture Year
* High Fail Rate badge indicates an MOT pass rate below 65% (failure rate above 35%).
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Brakes | 67.0% | 309 |
| 2 | Lamps, Reflectors And Electrical Equipment | 42.1% | 194 |
| 3 | Suspension | 34.9% | 161 |
| 4 | Steering | 28.9% | 133 |
| 5 | Body, Structure And General Items | 12.6% | 58 |
| 6 | Body, Chassis, Structure | 11.3% | 52 |
| 7 | Driver's View Of The Road | 10.6% | 49 |
| 8 | Exhaust, Fuel And Emissions | 10.2% | 47 |
| 9 | Tyres | 9.5% | 44 |
| 10 | Seat Belts And Supplementary Restraint Systems | 5.2% | 24 |
| 11 | Noise, Emissions And Leaks | 4.1% | 19 |
| 12 | Visibility | 3.3% | 15 |
| 13 | Road Wheels | 1.7% | 8 |
Failures per 10,000 Miles
avg. 239,487 miFor every 10,000 miles driven, this shows what percentage of MOT tests fail for each category. This accounts for how far cars are actually driven, not just raw pass/fail counts.
View as table
| Category | Rate / 10K mi | Raw % | Count |
|---|---|---|---|
| Brakes | 2.80 | 67.0% | 309 |
| Lamps & Electrical | 1.76 | 42.1% | 194 |
| Suspension | 1.46 | 34.9% | 161 |
| Steering | 1.20 | 28.9% | 133 |
| Body & Structure | 1.00 | 23.9% | 110 |
| Visibility | 0.58 | 13.9% | 64 |
| Emissions & Exhaust | 0.43 | 10.2% | 47 |
| Tyres | 0.40 | 9.5% | 44 |
| Seat Belts | 0.22 | 5.2% | 24 |
| Noise, emissions and leaks | 0.17 | 4.1% | 19 |
| Wheels | 0.07 | 1.7% | 8 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Mercedes 811d has 239,487 miles when tested for MOT.
📊 Mileage-Adjusted Failure Rate
How often this car fails MOT relative to how much it's driven — a fairer comparison than raw pass rate.
The Mercedes 811d has a mileage-adjusted failure rate of 1.65% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Mercedes 811d MOT Data
The Mercedes 811d is a rare vehicle in the UK, with 461 MOT test results recorded in our database spanning 7 manufacture years. It has an overall MOT pass rate of 60.5% and a failure rate of 39.5%, which is around the UK average of approximately 37%.
For Mercedes 811d owners, these results suggest average reliability — some preparation before MOT can improve pass chances. Focus your pre-MOT checks on brakes and suspension for the best chance of a first-time pass. Use our detailed year-by-year breakdown and failure analysis below to understand how your specific 811d is likely to perform.
Brakes — 51.4% of failures
Brakes issues account for 51.4% of MOT failures on the Mercedes 811d. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. Typical repair costs: £150–400. Pre-MOT check: Listen for squealing or grinding noises. Check brake pedal feel — if it feels spongy or goes to the floor, have the system inspected immediately. Look at brake pad thickness through the wheel spokes (minimum 3mm).
Suspension — 27.5% of failures
Suspension issues account for 27.5% of MOT failures on the Mercedes 811d. Suspension failures typically involve worn bushes, leaking shock absorbers, broken coil springs, and damaged suspension arms. These affect ride quality, tyre wear, and road holding. Typical repair costs: £200–500. Pre-MOT check: Look for uneven tyre wear, listen for clunking over bumps, and check if the car pulls to one side. A bouncy ride suggests worn shock absorbers. Visually inspect coil springs for cracks.
Steering — 23.9% of failures
Steering issues account for 23.9% of MOT failures on the Mercedes 811d. Steering failures include excessive play in the steering wheel, leaking power steering fluid, worn track rod ends, and damaged steering rack. These affect vehicle control and are closely related to suspension wear. Typical repair costs: £150–600. Pre-MOT check: Check for excessive steering wheel play (more than a few inches of free movement). Listen for whining from the power steering pump. Look for fluid leaks under the car near the front wheels.
Frequently Asked Questions
What is the MOT pass rate for the Mercedes 811d?
Based on 461 MOT tests in our database, the Mercedes 811d has an overall pass rate of 60.5% (39.5% fail rate).
What are the most common MOT failures on a Mercedes 811d?
The top 3 reasons a Mercedes 811d fails its MOT are: 1. Brakes (51.4%), 2. Suspension (27.5%), 3. Steering (23.9%). Check these areas before booking your MOT.
Is the Mercedes 811d reliable?
With a 39.5% MOT failure rate, the 811d is about average compared to the UK average of ~40%.
What should I check before an MOT on my Mercedes 811d?
Based on failure data, focus on: Brakes (51.4%); Suspension (27.5%); Steering (23.9%). These are the areas most likely to cause a fail. Also check all lights, tyres (minimum 1.6mm tread), and windscreen condition — these are quick wins that apply to all cars.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.