Mercedes Sl 63 MOT Pass Rate
Overall pass rate across all manufacture years, based on 1,881 real MOT test results. Failure rate: 11.2%.
Data from official DVSA MOT testing records
Mercedes Sl 63 MOT Reliability Overview
The Mercedes Sl 63 is a niche vehicle in the UK, with 1,881 MOT test results recorded in our database spanning 5 manufacture years. It has an overall MOT pass rate of 88.8% and a failure rate of 11.2%, which is well above the UK average of approximately 37%.
Based on this data, the Mercedes Sl 63 earns a "Excellent" reliability rating. The average Mercedes Sl 63 presents for MOT with approximately 27,927 miles on the clock. Manufacture year matters: 2011 models achieve the highest pass rate at 91.8%, while 2012 models have the lowest at 83.3%. This 8.5 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Mercedes Sl 63 is Tyres, affecting 9.3% 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 4.8%. Lamps, Reflectors and Electrical Equipment rounds out the top three at 3.7%. 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
📉 How Age Affects Reliability
MOT failure rate by vehicle age for the Mercedes Sl 63. The dashed red line marks when the manufacturer warranty typically expires (3 years).
Line chart showing MOT failure rate by vehicle age from 3 to 8 years, with warranty expiry marked at 3 years.
💡 What does the warranty cliff mean?
The Mercedes Sl 63 actually sees a 17% decrease in failure rate after the warranty period. This is likely due to survivorship bias — unreliable cars are already off the road by this age. Peak failure occurs at age 8 (16.9% fail rate).
Note: pass rates may improve for very old vehicles due to survivorship bias — only well-maintained cars remain on the road.
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 | 10.2% | 192 |
| 2 | Brakes | 4.9% | 93 |
| 3 | Lamps, Reflectors And Electrical Equipment | 4.6% | 86 |
| 4 | Suspension | 2.6% | 49 |
| 5 | Registration Plates And Vin | 1.8% | 34 |
| 6 | Driver's View Of The Road | 1.0% | 19 |
| 7 | Road Wheels | 0.9% | 17 |
| 8 | Noise, Emissions And Leaks | 0.5% | 9 |
| 9 | Steering | 0.5% | 9 |
| 10 | Body, Chassis, Structure | 0.2% | 4 |
| 11 | Identification Of The Vehicle | 0.2% | 4 |
| 12 | Non-component Advisories | 0.2% | 4 |
| 13 | Visibility | 0.2% | 3 |
| 14 | Body, Structure And General Items | 0.1% | 2 |
Failures per 10,000 Miles
avg. 27,927 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 | 3.66 | 10.2% | 192 |
| Brakes | 1.77 | 4.9% | 93 |
| Lamps & Electrical | 1.64 | 4.6% | 86 |
| Suspension | 0.93 | 2.6% | 49 |
| Registration Plates and VIN | 0.65 | 1.8% | 34 |
| Visibility | 0.42 | 1.2% | 22 |
| Wheels | 0.32 | 0.9% | 17 |
| Noise, emissions and leaks | 0.17 | 0.5% | 9 |
| Steering | 0.17 | 0.5% | 9 |
| Body & Structure | 0.12 | 0.3% | 6 |
| Identification of the vehicle | 0.08 | 0.2% | 4 |
| Non-component advisories | 0.08 | 0.2% | 4 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Mercedes Sl 63 has 27,927 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 Sl 63 has a mileage-adjusted failure rate of 4.01% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Mercedes Sl 63 MOT Data
The Mercedes Sl 63 is a niche vehicle in the UK, with 1,881 MOT test results recorded in our database spanning 5 manufacture years. It has an overall MOT pass rate of 88.8% and a failure rate of 11.2%, which is well above the UK average of approximately 37%.
For Mercedes Sl 63 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 Sl 63 is likely to perform.
Tyres — 9.3% of failures
Tyres issues account for 9.3% of MOT failures on the Mercedes Sl 63. 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 — 4.8% of failures
Brakes issues account for 4.8% of MOT failures on the Mercedes Sl 63. 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).
Lamps, Reflectors and Electrical Equipment — 3.7% of failures
Lamps, Reflectors and Electrical Equipment issues account for 3.7% of MOT failures on the Mercedes Sl 63. Lighting failures cover all external lights: headlights, tail lights, brake lights, indicators, fog lights, and reflectors. A single blown bulb will cause an MOT fail. This is one of the most preventable failure categories. Typical repair costs: £5–50. Pre-MOT check: Walk around the car and check every light — headlights (dipped and main beam), side lights, tail lights, brake lights, indicators, hazard lights, reverse light, rear fog light, and number plate lights. Replace any blown bulbs before the test.
Frequently Asked Questions
What is the MOT pass rate for the Mercedes Sl 63?
Based on 1,881 MOT tests in our database, the Mercedes Sl 63 has an overall pass rate of 88.8% (11.2% fail rate).
What are the most common MOT failures on a Mercedes Sl 63?
The top 3 reasons a Mercedes Sl 63 fails its MOT are: 1. Tyres (9.3%), 2. Brakes (4.8%), 3. Lamps, Reflectors and Electrical Equipment (3.7%). Check these areas before booking your MOT.
Is the Mercedes Sl 63 reliable?
With a 11.2% MOT failure rate, the Sl 63 is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Mercedes Sl 63?
Based on failure data, focus on: Tyres (9.3%); Brakes (4.8%); Lamps, Reflectors and Electrical Equipment (3.7%). 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.