2008 Mercedes Gl420 Cdi 4-matic A MOT Pass Rate
Pass rate for Gl420 Cdi 4-matic A models manufactured in 2008, based on 378 real MOT test results.
Data from official DVSA MOT testing records
This page shows all Gl420 Cdi 4-matic A cars tested in 2008. Want to see how cars built in 2008 hold up over time?
View 2008 Mercedes Gl420 Cdi 4-matic A vintage page → (82.0% current pass rate)2008 Mercedes Gl420 Cdi 4-matic A MOT Analysis
The 2008 Mercedes Gl420 Cdi 4-matic A has an MOT pass rate of 81.0% based on 378 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 62,134 miles on the odometer. With a 19.0% failure rate, the 2008 Gl420 Cdi 4-matic A is rated as "Excellent" for MOT reliability.
The leading cause of MOT failure for the 2008 Mercedes Gl420 Cdi 4-matic A is Brakes, responsible for 4.5% of failures. 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 range from £150–400. Suspension is the second most common issue at 2.1%. Tyres follows at 1.6%.
Top failures specific to 2008 models only. The overall Gl420 Cdi 4-matic A page may show different rankings.
What Fails Most
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Brakes | 4.5% | 17 |
| 2 | Suspension | 2.1% | 8 |
| 3 | Tyres | 1.6% | 6 |
| 4 | Lamps, Reflectors And Electrical Equipment | 1.3% | 5 |
| 5 | Driver's View Of The Road | 0.8% | 3 |
| 6 | Non-component Advisories | 0.5% | 2 |
| 7 | Registration Plates And Vin | 0.3% | 1 |
| 8 | Seat Belts And Supplementary Restraint Systems | 0.3% | 1 |
Failures per 10,000 Miles
avg. 62,134 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 | 0.72 | 4.5% | 17 |
| Suspension | 0.34 | 2.1% | 8 |
| Tyres | 0.26 | 1.6% | 6 |
| Lamps & Electrical | 0.21 | 1.3% | 5 |
| Visibility | 0.13 | 0.8% | 3 |
| Non-component advisories | 0.09 | 0.5% | 2 |
| Registration Plates and VIN | 0.04 | 0.3% | 1 |
| Seat Belts | 0.04 | 0.3% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 2008 Mercedes Gl420 Cdi 4-matic A has an MOT pass rate of 81.0% based on 378 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 62,134 miles on the odometer. With a 19.0% failure rate, the 2008 Gl420 Cdi 4-matic A is rated as "Excellent" for MOT reliability.
If you own or are considering buying a 2008 Mercedes Gl420 Cdi 4-matic A, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to brakes: 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). At 62,134 average miles, these vehicles are in the mid-range where component wear starts to become a factor.
Brakes — 4.5% of failures
Brakes issues account for 4.5% of MOT failures on 2008 Mercedes Gl420 Cdi 4-matic A models. 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 — 2.1% of failures
Suspension issues account for 2.1% of MOT failures on 2008 Mercedes Gl420 Cdi 4-matic A models. 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.
Tyres — 1.6% of failures
Tyres issues account for 1.6% of MOT failures on 2008 Mercedes Gl420 Cdi 4-matic A models. 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.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.