1977 Porsche 911 MOT Pass Rate
Pass rate for 911 models manufactured in 1977, based on 1,511 real MOT test results.
Data from official DVSA MOT testing records
This page shows all 911 cars tested in 1977. Want to see how cars built in 1977 hold up over time?
View 1977 Porsche 911 vintage page → (90.3% current pass rate)1977 Porsche 911 MOT Analysis
The 1977 Porsche 911 has an MOT pass rate of 70.6% based on 1,511 tests — above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 107,204 miles on the odometer. With a 29.4% failure rate, the 1977 911 is rated as "Very Good" for MOT reliability.
The leading cause of MOT failure for the 1977 Porsche 911 is Noise, emissions and leaks, responsible for 0.1% 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 1977 models only. The overall 911 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 | Noise, Emissions And Leaks | 0.1% | 1 |
Failures per 10,000 Miles
avg. 107,204 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 |
|---|---|---|---|
| Noise, emissions and leaks | 0.01 | 0.1% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1977 Porsche 911 has an MOT pass rate of 70.6% based on 1,511 tests — above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 107,204 miles on the odometer. With a 29.4% failure rate, the 1977 911 is rated as "Very Good" for MOT reliability.
If you own or are considering buying a 1977 Porsche 911, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to noise, emissions and leaks: 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 107,204 miles, these vehicles are in the higher-mileage bracket where wear-related failures become more common.
Noise, emissions and leaks — 0.1% of failures
Noise, emissions and leaks issues account for 0.1% of MOT failures on 1977 Porsche 911 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.