1978 Porsche Unclassified MOT Pass Rate
Pass rate for Unclassified models manufactured in 1978, based on 38 real MOT test results.
Data from official DVSA MOT testing records
1978 Porsche Unclassified MOT Analysis
The 1978 Porsche Unclassified has an MOT pass rate of 63.2% based on 38 tests — around the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 115,232 miles on the odometer. With a 36.8% failure rate, the 1978 Unclassified is rated as "Average" for MOT reliability.
The leading cause of MOT failure for the 1978 Porsche Unclassified is Noise, emissions and leaks, responsible for 2.6% 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+. Seat belts and supplementary restraint systems is the second most common issue at 2.6%. Suspension follows at 2.6%.
Top failures specific to 1978 models only. The overall Unclassified 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 | 2.6% | 1 |
| 2 | Seat Belts And Supplementary Restraint Systems | 2.6% | 1 |
| 3 | Suspension | 2.6% | 1 |
| 4 | Body, Chassis, Structure | 2.6% | 1 |
| 5 | Brakes | 2.6% | 1 |
Failures per 10,000 Miles
avg. 115,232 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 | 0.23 | 2.6% | 1 |
| Seat Belts | 0.23 | 2.6% | 1 |
| Suspension | 0.23 | 2.6% | 1 |
| Body & Structure | 0.23 | 2.6% | 1 |
| Brakes | 0.23 | 2.6% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1978 Porsche Unclassified has an MOT pass rate of 63.2% based on 38 tests — around the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 115,232 miles on the odometer. With a 36.8% failure rate, the 1978 Unclassified is rated as "Average" for MOT reliability.
If you own or are considering buying a 1978 Porsche Unclassified, budget for potential repairs before each MOT. 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 115,232 miles, these vehicles are in the higher-mileage bracket where wear-related failures become more common.
Noise, emissions and leaks — 2.6% of failures
Noise, emissions and leaks issues account for 2.6% of MOT failures on 1978 Porsche Unclassified 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.
Seat belts and supplementary restraint systems — 2.6% of failures
Seat belts and supplementary restraint systems issues account for 2.6% of MOT failures on 1978 Porsche Unclassified models. Seat belt failures include frayed or cut webbing, faulty retractors, buckles that don't latch properly, and missing or damaged anchorages. All fitted seat belts must be functional. Typical repair costs: £50–200 per belt. Pre-MOT check: Pull each seat belt fully out and check for fraying, cuts, or fading. Ensure each belt retracts smoothly and the buckle clicks securely. Check the pre-tensioner warning light on the dashboard.
Suspension — 2.6% of failures
Suspension issues account for 2.6% of MOT failures on 1978 Porsche Unclassified 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.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.