Mercedes Gl 320 MOT Pass Rate
Overall pass rate across all manufacture years, based on 7,831 real MOT test results. Failure rate: 25.1%.
Data from official DVSA MOT testing records
Mercedes Gl 320 MOT Reliability Overview
The Mercedes Gl 320 is a less common vehicle in the UK, with 7,831 MOT test results recorded in our database spanning 5 manufacture years. It has an overall MOT pass rate of 74.9% and a failure rate of 25.1%, which is above the UK average of approximately 37%.
Based on this data, the Mercedes Gl 320 earns a "Very Good" reliability rating. The average Mercedes Gl 320 presents for MOT with approximately 77,850 miles on the clock. Manufacture year matters: 2010 models achieve the highest pass rate at 82.9%, while 2006 models have the lowest at 69.5%. This 13.4 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Mercedes Gl 320 is Brakes, affecting 21.3% 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 16.0%. Lamps, Reflectors and Electrical Equipment rounds out the top three at 14.3%. 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 3 vintages — click year chips to highlight.
Multi-line chart showing how different Mercedes Gl 320 vintages degrade over time, from age 3 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.
📉 How Age Affects Reliability
MOT failure rate by vehicle age for the Mercedes Gl 320. 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 13 years, with warranty expiry marked at 3 years.
💡 What does the warranty cliff mean?
The Mercedes Gl 320 ages relatively gracefully. The failure rate increase of 13% after warranty is below average, suggesting good long-term reliability. Peak failure occurs at age 8 (31.1% 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 | Brakes | 22.2% | 1,741 |
| 2 | Tyres | 19.2% | 1,503 |
| 3 | Lamps, Reflectors And Electrical Equipment | 19.2% | 1,507 |
| 4 | Suspension | 9.7% | 758 |
| 5 | Driver's View Of The Road | 2.9% | 230 |
| 6 | Noise, Emissions And Leaks | 2.1% | 164 |
| 7 | Registration Plates And Vin | 1.9% | 150 |
| 8 | Seat Belts And Supplementary Restraint Systems | 1.8% | 147 |
| 9 | Non-component Advisories | 1.4% | 106 |
| 10 | Steering | 1.1% | 83 |
| 11 | Body, Chassis, Structure | 0.7% | 53 |
| 12 | Visibility | 0.6% | 45 |
| 13 | Exhaust, Fuel And Emissions | 0.5% | 38 |
Failures per 10,000 Miles
avg. 77,850 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 |
|---|---|---|---|
| Brakes | 2.86 | 22.2% | 1,741 |
| Tyres | 2.47 | 19.2% | 1,503 |
| Lamps & Electrical | 2.47 | 19.2% | 1,507 |
| Suspension | 1.24 | 9.7% | 758 |
| Visibility | 0.45 | 3.5% | 275 |
| Noise, emissions and leaks | 0.27 | 2.1% | 164 |
| Registration Plates and VIN | 0.25 | 1.9% | 150 |
| Seat Belts | 0.24 | 1.8% | 147 |
| Non-component advisories | 0.17 | 1.4% | 106 |
| Steering | 0.14 | 1.1% | 83 |
| Body & Structure | 0.09 | 0.7% | 53 |
| Emissions & Exhaust | 0.06 | 0.5% | 38 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Mercedes Gl 320 has 77,850 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 Gl 320 has a mileage-adjusted failure rate of 3.22% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Mercedes Gl 320 MOT Data
The Mercedes Gl 320 is a less common vehicle in the UK, with 7,831 MOT test results recorded in our database spanning 5 manufacture years. It has an overall MOT pass rate of 74.9% and a failure rate of 25.1%, which is above the UK average of approximately 37%.
For Mercedes Gl 320 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 Gl 320 is likely to perform.
Brakes — 21.3% of failures
Brakes issues account for 21.3% of MOT failures on the Mercedes Gl 320. 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 — 16.0% of failures
Tyres issues account for 16.0% of MOT failures on the Mercedes Gl 320. 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.
Lamps, Reflectors and Electrical Equipment — 14.3% of failures
Lamps, Reflectors and Electrical Equipment issues account for 14.3% of MOT failures on the Mercedes Gl 320. 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 Gl 320?
Based on 7,831 MOT tests in our database, the Mercedes Gl 320 has an overall pass rate of 74.9% (25.1% fail rate).
What are the most common MOT failures on a Mercedes Gl 320?
The top 3 reasons a Mercedes Gl 320 fails its MOT are: 1. Brakes (21.3%), 2. Tyres (16.0%), 3. Lamps, Reflectors and Electrical Equipment (14.3%). Check these areas before booking your MOT.
Is the Mercedes Gl 320 reliable?
With a 25.1% MOT failure rate, the Gl 320 is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Mercedes Gl 320?
Based on failure data, focus on: Brakes (21.3%); Tyres (16.0%); Lamps, Reflectors and Electrical Equipment (14.3%). 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.