Mercedes S320 Cdi MOT Pass Rate
Overall pass rate across all manufacture years, based on 61 real MOT test results. Failure rate: 26.2%.
Data from official DVSA MOT testing records
Mercedes S320 Cdi MOT Reliability Overview
The Mercedes S320 Cdi is a rare vehicle in the UK, with 61 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 73.8% and a failure rate of 26.2%, which is above the UK average of approximately 37%.
Based on this data, the Mercedes S320 Cdi earns a "Very Good" reliability rating. The average Mercedes S320 Cdi presents for MOT with approximately 105,340 miles on the clock.
The most common MOT failure for the Mercedes S320 Cdi is Tyres, affecting 26.2% of all tests. Tyre failures include tread depth below the legal minimum of 1.6mm, cuts, bulges, exposed cords, and incorrect tyre pressure. Tyres are one of the most common and easiest-to-prevent MOT failures. The second most common issue is Suspension at 14.8%. Brakes rounds out the top three at 13.1%. 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
* 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 | Tyres | 27.9% | 17 |
| 2 | Lamps, Reflectors And Electrical Equipment | 18.0% | 11 |
| 3 | Brakes | 16.4% | 10 |
| 4 | Suspension | 14.8% | 9 |
| 5 | Driver's View Of The Road | 6.6% | 4 |
| 6 | Seat Belts And Supplementary Restraint Systems | 3.3% | 2 |
| 7 | Noise, Emissions And Leaks | 1.6% | 1 |
| 8 | Visibility | 1.6% | 1 |
| 9 | Registration Plates And Vin | 1.6% | 1 |
| 10 | Identification Of The Vehicle | 1.6% | 1 |
| 11 | Non-component Advisories | 1.6% | 1 |
Failures per 10,000 Miles
avg. 105,340 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 |
|---|---|---|---|
| Tyres | 2.65 | 27.9% | 17 |
| Lamps & Electrical | 1.71 | 18.0% | 11 |
| Brakes | 1.56 | 16.4% | 10 |
| Suspension | 1.40 | 14.8% | 9 |
| Visibility | 0.78 | 8.2% | 5 |
| Seat Belts | 0.31 | 3.3% | 2 |
| Noise, emissions and leaks | 0.16 | 1.6% | 1 |
| Registration Plates and VIN | 0.16 | 1.6% | 1 |
| Identification of the vehicle | 0.16 | 1.6% | 1 |
| Non-component advisories | 0.16 | 1.6% | 1 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Mercedes S320 Cdi has 105,340 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 S320 Cdi has a mileage-adjusted failure rate of 2.49% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Mercedes S320 Cdi MOT Data
The Mercedes S320 Cdi is a rare vehicle in the UK, with 61 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 73.8% and a failure rate of 26.2%, which is above the UK average of approximately 37%.
For Mercedes S320 Cdi owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on tyres 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 S320 Cdi is likely to perform.
Tyres — 26.2% of failures
Tyres issues account for 26.2% of MOT failures on the Mercedes S320 Cdi. Tyre failures include tread depth below the legal minimum of 1.6mm, cuts, bulges, exposed cords, and incorrect tyre pressure. Tyres are one of the most common and easiest-to-prevent MOT failures. Typical repair costs: £50–200 per tyre. Pre-MOT check: Check tread depth with a 20p coin — if the outer band is visible, the tyre is too worn. Look for bulges, cuts, or embedded objects. Ensure all tyres match the recommended size and load rating.
Suspension — 14.8% of failures
Suspension issues account for 14.8% of MOT failures on the Mercedes S320 Cdi. 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.
Brakes — 13.1% of failures
Brakes issues account for 13.1% of MOT failures on the Mercedes S320 Cdi. 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).
Frequently Asked Questions
What is the MOT pass rate for the Mercedes S320 Cdi?
Based on 61 (based on limited data) MOT tests in our database, the Mercedes S320 Cdi has an overall pass rate of 73.8% (26.2% fail rate).
What are the most common MOT failures on a Mercedes S320 Cdi?
The top 3 reasons a Mercedes S320 Cdi fails its MOT are: 1. Tyres (26.2%), 2. Suspension (14.8%), 3. Brakes (13.1%). Check these areas before booking your MOT.
Is the Mercedes S320 Cdi reliable?
With a 26.2% MOT failure rate, the S320 Cdi is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Mercedes S320 Cdi?
Based on failure data, focus on: Tyres (26.2%); Suspension (14.8%); Brakes (13.1%). 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.