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Mercedes R350 Cdi MOT Pass Rate

Overall pass rate across all manufacture years, based on 70 real MOT test results. Failure rate: 24.3%.

75.7%
Pass Rate
24.3%
Fail Rate
70
Total Tests
Brakes
Top Failure

Data from official DVSA MOT testing records

Mercedes R350 Cdi MOT Reliability Overview

The Mercedes R350 Cdi is a rare vehicle in the UK, with 70 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 75.7% and a failure rate of 24.3%, which is well above the UK average of approximately 37%.

Based on this data, the Mercedes R350 Cdi earns a "Excellent" reliability rating. The average Mercedes R350 Cdi presents for MOT with approximately 91,008 miles on the clock.

The most common MOT failure for the Mercedes R350 Cdi is Brakes, affecting 25.7% 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 Tyres at 15.7%. Body, chassis, structure rounds out the top three at 15.7%. Together, these top 3 failure categories account for a significant portion of all MOT failures for this model.

⚠ Based on limited data (70 tests)

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

What Fails Most

⚖️ 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
1Brakes25.7%18
2Body, Chassis, Structure15.7%11
3Tyres15.7%11
4Lamps, Reflectors And Electrical Equipment14.3%10
5Noise, Emissions And Leaks10.0%7
6Suspension5.7%4
7Non-component Advisories1.4%1
8Road Wheels1.4%1
9Visibility1.4%1
10Seat Belts And Supplementary Restraint Systems1.4%1

Failures per 10,000 Miles

avg. 91,008 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.

Brakes2.83% per 10K miBody & Structure1.73% per 10K miTyres1.73% per 10K miLamps & Electrical1.57% per 10K miNoise, emissions and leaks1.10% per 10K miSuspension0.63% per 10K miNon-component advisories0.16% per 10K miWheels0.16% per 10K miVisibility0.16% per 10K miSeat Belts0.16% per 10K mi
View as table
Mileage-normalised failure rates by category
CategoryRate / 10K miRaw %Count
Brakes2.8325.7%18
Body & Structure1.7315.7%11
Tyres1.7315.7%11
Lamps & Electrical1.5714.3%10
Noise, emissions and leaks1.1010.0%7
Suspension0.635.7%4
Non-component advisories0.161.4%1
Wheels0.161.4%1
Visibility0.161.4%1
Seat Belts0.161.4%1

🚗 Similar Cars to Consider

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Mileage at MOT

91,008
Mean
90,932
Median
64,459
25th Percentile
106,980
75th Percentile

The average Mercedes R350 Cdi has 91,008 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.

2.67%
Fail Rate per 10K Miles
Average across all makes: 5.38%
24.3%
Overall Fail Rate
91,008 avg miles
✅ Good — below average failure rate

The Mercedes R350 Cdi has a mileage-adjusted failure rate of 2.67% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.

About Mercedes R350 Cdi MOT Data

The Mercedes R350 Cdi is a rare vehicle in the UK, with 70 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 75.7% and a failure rate of 24.3%, which is well above the UK average of approximately 37%.

For Mercedes R350 Cdi owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on brakes and tyres 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 R350 Cdi is likely to perform.

Brakes — 25.7% of failures

Brakes issues account for 25.7% of MOT failures on the Mercedes R350 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).

Tyres — 15.7% of failures

Tyres issues account for 15.7% of MOT failures on the Mercedes R350 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.

Body, chassis, structure — 15.7% of failures

Body, chassis, structure issues account for 15.7% of MOT failures on the Mercedes R350 Cdi. Body and structure failures include excessive corrosion, sharp edges, loose panels, and damage to the vehicle frame. Rust is the primary concern, especially on older vehicles or those exposed to road salt. Typical repair costs: £100–500+. Pre-MOT check: Inspect sills, wheel arches, door bottoms, and the chassis for rust. Surface rust is acceptable but structural corrosion or holes will fail. Check that all doors, bonnet, and boot close securely.

Frequently Asked Questions

What is the MOT pass rate for the Mercedes R350 Cdi?

Based on 70 (based on limited data) MOT tests in our database, the Mercedes R350 Cdi has an overall pass rate of 75.7% (24.3% fail rate).

What are the most common MOT failures on a Mercedes R350 Cdi?

The top 3 reasons a Mercedes R350 Cdi fails its MOT are: 1. Brakes (25.7%), 2. Tyres (15.7%), 3. Body, chassis, structure (15.7%). Check these areas before booking your MOT.

Is the Mercedes R350 Cdi reliable?

With a 24.3% MOT failure rate, the R350 Cdi is more reliable than average compared to the UK average of ~40%.

What should I check before an MOT on my Mercedes R350 Cdi?

Based on failure data, focus on: Brakes (25.7%); Tyres (15.7%); Body, chassis, structure (15.7%). 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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