Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto MOT Pass Rate
Overall pass rate across all manufacture years, based on 4,494 real MOT test results. Failure rate: 11.5%.
Data from official DVSA MOT testing records
Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto MOT Reliability Overview
The Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto is a niche vehicle in the UK, with 4,494 MOT test results recorded in our database spanning 4 manufacture years. It has an overall MOT pass rate of 88.5% and a failure rate of 11.5%, which is well above the UK average of approximately 37%.
Based on this data, the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto earns a "Excellent" reliability rating. The average Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto presents for MOT with approximately 58,686 miles on the clock. Manufacture year matters: 2013 models achieve the highest pass rate at 90.7%, while 2011 models have the lowest at 86.7%. This 4.0 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto is Tyres, affecting 11.8% 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 Brakes at 6.8%. Suspension rounds out the top three at 4.2%. 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
Best Year to Buy
📈 How Each Vintage Ages
Tracking how each manufacture year's MOT pass rate changes as the car ages. Showing 4 vintages — click year chips to highlight.
Multi-line chart showing how different Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto vintages degrade over time, from age 1 to 20 years.
Only vintages with 100+ tests in at least 3 different test years are shown. Fleet average is the UK-wide pass rate for all cars at each age.
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 | Tyres | 11.9% | 536 |
| 2 | Brakes | 6.8% | 304 |
| 3 | Suspension | 4.2% | 188 |
| 4 | Lamps, Reflectors And Electrical Equipment | 3.3% | 147 |
| 5 | Driver's View Of The Road | 1.5% | 68 |
| 6 | Registration Plates And Vin | 0.9% | 41 |
| 7 | Road Wheels | 0.6% | 28 |
| 8 | Steering | 0.3% | 13 |
| 9 | Non-component Advisories | 0.3% | 12 |
| 10 | Exhaust, Fuel And Emissions | 0.1% | 5 |
| 11 | Seat Belts And Supplementary Restraint Systems | 0.1% | 4 |
| 12 | Body, Structure And General Items | 0.1% | 4 |
Failures per 10,000 Miles
avg. 58,686 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 | 2.03 | 11.9% | 536 |
| Brakes | 1.15 | 6.8% | 304 |
| Suspension | 0.71 | 4.2% | 188 |
| Lamps & Electrical | 0.56 | 3.3% | 147 |
| Visibility | 0.26 | 1.5% | 68 |
| Registration Plates and VIN | 0.16 | 0.9% | 41 |
| Wheels | 0.11 | 0.6% | 28 |
| Steering | 0.05 | 0.3% | 13 |
| Non-component advisories | 0.05 | 0.3% | 12 |
| Emissions & Exhaust | 0.02 | 0.1% | 5 |
| Seat Belts | 0.02 | 0.1% | 4 |
| Body & Structure | 0.02 | 0.1% | 4 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto has 58,686 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-Benz S350 Bluetec B-fcy L Cdi Auto has a mileage-adjusted failure rate of 1.96% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto MOT Data
The Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto is a niche vehicle in the UK, with 4,494 MOT test results recorded in our database spanning 4 manufacture years. It has an overall MOT pass rate of 88.5% and a failure rate of 11.5%, which is well above the UK average of approximately 37%.
For Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on tyres and brakes 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 S350 Bluetec B-fcy L Cdi Auto is likely to perform.
Tyres — 11.8% of failures
Tyres issues account for 11.8% of MOT failures on the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto. 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.
Brakes — 6.8% of failures
Brakes issues account for 6.8% of MOT failures on the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto. 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 — 4.2% of failures
Suspension issues account for 4.2% of MOT failures on the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto. 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.
Frequently Asked Questions
What is the MOT pass rate for the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto?
Based on 4,494 MOT tests in our database, the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto has an overall pass rate of 88.5% (11.5% fail rate).
What are the most common MOT failures on a Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto?
The top 3 reasons a Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto fails its MOT are: 1. Tyres (11.8%), 2. Brakes (6.8%), 3. Suspension (4.2%). Check these areas before booking your MOT.
Is the Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto reliable?
With a 11.5% MOT failure rate, the S350 Bluetec B-fcy L Cdi Auto is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Mercedes-Benz S350 Bluetec B-fcy L Cdi Auto?
Based on failure data, focus on: Tyres (11.8%); Brakes (6.8%); Suspension (4.2%). 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.