1994 Mercedes S 420 MOT Pass Rate
Pass rate for S 420 models manufactured in 1994, based on 81 real MOT test results.
Data from official DVSA MOT testing records
1994 Mercedes S 420 MOT Analysis
The 1994 Mercedes S 420 has an MOT pass rate of 61.7% based on 81 tests — around the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 127,734 miles on the odometer. With a 38.3% failure rate, the 1994 S 420 is rated as "Average" for MOT reliability.
The leading cause of MOT failure for the 1994 Mercedes S 420 is Exhaust, Fuel and Emissions, responsible for 1.2% of failures. Emissions failures occur when exhaust gases exceed legal limits for carbon monoxide (CO), hydrocarbons (HC), or particulate matter (diesel). Common causes include faulty oxygen sensors, clogged catalytic converters, or DPF issues on diesel vehicles. Typical repair costs range from £100–1,000+.
Top failures specific to 1994 models only. The overall S 420 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 | Exhaust, Fuel And Emissions | 1.2% | 1 |
Failures per 10,000 Miles
avg. 127,734 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.
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| Category | Rate / 10K mi | Raw % | Count |
|---|---|---|---|
| Emissions & Exhaust | 0.10 | 1.2% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1994 Mercedes S 420 has an MOT pass rate of 61.7% based on 81 tests — around the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 127,734 miles on the odometer. With a 38.3% failure rate, the 1994 S 420 is rated as "Average" for MOT reliability.
If you own or are considering buying a 1994 Mercedes S 420, budget for potential repairs before each MOT. Before your MOT, pay particular attention to exhaust, fuel and emissions: If the engine management light is on, get it diagnosed before the MOT. For diesel cars, ensure the DPF has completed a regeneration cycle. Regular servicing and using premium fuel before the test can help. With an average mileage of 127,734 miles, these vehicles are in the higher-mileage bracket where wear-related failures become more common.
Exhaust, Fuel and Emissions — 1.2% of failures
Exhaust, Fuel and Emissions issues account for 1.2% of MOT failures on 1994 Mercedes S 420 models. Emissions failures occur when exhaust gases exceed legal limits for carbon monoxide (CO), hydrocarbons (HC), or particulate matter (diesel). Common causes include faulty oxygen sensors, clogged catalytic converters, or DPF issues on diesel vehicles. Typical repair costs: £100–1,000+. Pre-MOT check: If the engine management light is on, get it diagnosed before the MOT. For diesel cars, ensure the DPF has completed a regeneration cycle. Regular servicing and using premium fuel before the test can help.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.