1991 Porsche 911 MOT Pass Rate
Pass rate for 911 models manufactured in 1991, based on 5,917 real MOT test results.
Data from official DVSA MOT testing records
This page shows all 911 cars tested in 1991. Want to see how cars built in 1991 hold up over time?
View 1991 Porsche 911 vintage page → (89.9% current pass rate)1991 Porsche 911 MOT Analysis
The 1991 Porsche 911 has an MOT pass rate of 78.4% based on 5,917 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 94,156 miles on the odometer. With a 21.6% failure rate, the 1991 911 is rated as "Excellent" for MOT reliability.
The leading cause of MOT failure for the 1991 Porsche 911 is Lamps, reflectors and electrical equipment, responsible for 1.5% of failures. 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 range from £5–50. Tyres is the second most common issue at 0.7%. Visibility follows at 0.5%.
Top failures specific to 1991 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 | Lamps, Reflectors And Electrical Equipment | 1.5% | 90 |
| 2 | Tyres | 0.7% | 41 |
| 3 | Visibility | 0.5% | 27 |
| 4 | Suspension | 0.3% | 20 |
| 5 | Noise, Emissions And Leaks | 0.3% | 16 |
| 6 | Body, Chassis, Structure | 0.2% | 11 |
| 7 | Identification Of The Vehicle | 0.2% | 10 |
| 8 | Brakes | 0.1% | 5 |
| 9 | Steering | 0.1% | 4 |
| 10 | Non-component Advisories | 0.1% | 4 |
Failures per 10,000 Miles
avg. 94,156 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 |
|---|---|---|---|
| Lamps & Electrical | 0.16 | 1.5% | 90 |
| Tyres | 0.07 | 0.7% | 41 |
| Visibility | 0.05 | 0.5% | 27 |
| Suspension | 0.04 | 0.3% | 20 |
| Noise, emissions and leaks | 0.03 | 0.3% | 16 |
| Body & Structure | 0.02 | 0.2% | 11 |
| Identification of the vehicle | 0.02 | 0.2% | 10 |
| Brakes | 0.01 | 0.1% | 5 |
| Steering | 0.01 | 0.1% | 4 |
| Non-component advisories | 0.01 | 0.1% | 4 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1991 Porsche 911 has an MOT pass rate of 78.4% based on 5,917 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 94,156 miles on the odometer. With a 21.6% failure rate, the 1991 911 is rated as "Excellent" for MOT reliability.
If you own or are considering buying a 1991 Porsche 911, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to lamps, reflectors and electrical equipment: 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. With an average mileage of 94,156 miles, these vehicles are in the higher-mileage bracket where wear-related failures become more common.
Lamps, reflectors and electrical equipment — 1.5% of failures
Lamps, reflectors and electrical equipment issues account for 1.5% of MOT failures on 1991 Porsche 911 models. 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.
Tyres — 0.7% of failures
Tyres issues account for 0.7% of MOT failures on 1991 Porsche 911 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.
Visibility — 0.5% of failures
Visibility issues account for 0.5% of MOT failures on 1991 Porsche 911 models. Visibility failures relate to the windscreen, wipers, washers, mirrors, and view-obstructing damage. Cracks in the windscreen swept area, ineffective wipers, or empty washer bottles are common causes. Typical repair costs: £10–300. Pre-MOT check: Check the windscreen for chips and cracks — damage larger than 10mm in the driver's swept area or 40mm elsewhere will fail. Test washers and wipers. Ensure both door mirrors are intact and adjustable.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.