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Mercedes S350cdi MOT Pass Rate

Overall pass rate across all manufacture years, based on 47 real MOT test results. Failure rate: 21.3%.

78.7%
Pass Rate
21.3%
Fail Rate
47
Total Tests
Tyres
Top Failure

Data from official DVSA MOT testing records

Mercedes S350cdi MOT Reliability Overview

The Mercedes S350cdi is a rare vehicle in the UK, with 47 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 78.7% and a failure rate of 21.3%, which is well above the UK average of approximately 37%.

Based on this data, the Mercedes S350cdi earns a "Excellent" reliability rating. The average Mercedes S350cdi presents for MOT with approximately 71,778 miles on the clock.

The most common MOT failure for the Mercedes S350cdi is Tyres, affecting 19.1% 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 12.8%. Identification of the vehicle rounds out the top three at 4.3%. Together, these top 3 failure categories account for a significant portion of all MOT failures for this model.

⚠ Based on limited data (47 tests)

Top failures across all manufacture years combined. Individual year pages may show different top failures.

What Fails Most

Tyres 19.1%
Brakes 12.8%
Identification of the vehicle 4.3%
⚖️ Compare

* 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
MOT failure categories ranked by failure rate
RankFailure CategoryRate (%)Count
1Tyres21.3%10
2Brakes12.8%6
3Identification Of The Vehicle4.3%2
4Suspension2.1%1
5Lamps, Reflectors And Electrical Equipment2.1%1
6Body, Chassis, Structure2.1%1
7Registration Plates And Vin2.1%1

Failures per 10,000 Miles

avg. 71,778 mi

For 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.

Tyres2.96% per 10K miBrakes1.78% per 10K miIdentification of the vehicle0.59% per 10K miSuspension0.30% per 10K miLamps & Electrical0.30% per 10K miBody & Structure0.30% per 10K miRegistration Plates and VIN0.30% per 10K mi
View as table
Mileage-normalised failure rates by category
CategoryRate / 10K miRaw %Count
Tyres2.9621.3%10
Brakes1.7812.8%6
Identification of the vehicle0.594.3%2
Suspension0.302.1%1
Lamps & Electrical0.302.1%1
Body & Structure0.302.1%1
Registration Plates and VIN0.302.1%1

🚗 Similar Cars to Consider

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No comparable models

Mileage at MOT

71,778
Mean
73,633
Median
42,786
25th Percentile
103,985
75th Percentile

The average Mercedes S350cdi has 71,778 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.

2.97%
Fail Rate per 10K Miles
Average across all makes: 5.38%
21.3%
Overall Fail Rate
71,778 avg miles
✅ Good — below average failure rate

The Mercedes S350cdi has a mileage-adjusted failure rate of 2.97% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.

About Mercedes S350cdi MOT Data

The Mercedes S350cdi is a rare vehicle in the UK, with 47 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 78.7% and a failure rate of 21.3%, which is well above the UK average of approximately 37%.

For Mercedes S350cdi 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 S350cdi is likely to perform.

Tyres — 19.1% of failures

Tyres issues account for 19.1% of MOT failures on the Mercedes S350cdi. 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 — 12.8% of failures

Brakes issues account for 12.8% of MOT failures on the Mercedes S350cdi. 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).

Identification of the vehicle — 4.3% of failures

Identification of the vehicle issues account for 4.3% of MOT failures on the Mercedes S350cdi. Identification failures relate to the Vehicle Identification Number (VIN) and registration plate. The VIN must be permanently displayed and legible, and the registration plate must meet British Standard formatting. Typical repair costs: £10–50. Pre-MOT check: Ensure the VIN plate is visible and legible (usually in the windscreen or under the bonnet). Check that number plates are clean, undamaged, and use the correct font and spacing.

Frequently Asked Questions

What is the MOT pass rate for the Mercedes S350cdi?

Based on 47 (based on limited data) MOT tests in our database, the Mercedes S350cdi has an overall pass rate of 78.7% (21.3% fail rate).

What are the most common MOT failures on a Mercedes S350cdi?

The top 3 reasons a Mercedes S350cdi fails its MOT are: 1. Tyres (19.1%), 2. Brakes (12.8%), 3. Identification of the vehicle (4.3%). Check these areas before booking your MOT.

Is the Mercedes S350cdi reliable?

With a 21.3% MOT failure rate, the S350cdi is more reliable than average compared to the UK average of ~40%.

What should I check before an MOT on my Mercedes S350cdi?

Based on failure data, focus on: Tyres (19.1%); Brakes (12.8%); Identification of the vehicle (4.3%). 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.

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