Porsche 928 S: MOT pass rate and reliability data

The Porsche 928 S passes its MOT first time more often than the average UK car, by 4.8 percentage points. These figures come from the DVSA's full year of anonymised MOT results, covering 513 individual Porsche 928 S tests. Nothing here is an estimate or a survey.

The numbers

What this means if you are buying one

A 81.5% first-time pass rate means roughly 19 in every 100 Porsche 928 S presented for MOT fail on the first attempt. That is better than average, so a well-kept example is a reasonably safe used buy. The average Porsche 928 S tested had covered 110,676 miles and was built around 1988.

What this means at salvage auction

Pass rate is a proxy for what a car costs to keep on the road. The Porsche 928 S sits 4.8 points above the national average, ranked 1,398 of 2,005 models. On one bought as repairable salvage, the mechanical side is less likely to spring surprises, so your repair estimate should hold up reasonably well.

Before you bid: run the lot through the analyzer, check the car's own record, check the mileage, decode the VIN, and if it carries a marker use the write-off value calculator. Or compare it against another model.

Looking at a specific Porsche 928 S rather than the model in general? The free check covers its MOT and mileage history, and the full HPI report confirms the insurance write-off category, outstanding finance and whether it is recorded stolen, from licensed data for 5 credits. Already own one that has been damaged? Work out whether fixing it beats selling it with the repair or scrap calculator, and see recorded closing bids for damaged Porsche 928 S at UK salvage auction.

Most common MOT failures on a Porsche 928 S

1. An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning, 4.5% of tests (10.19x the national rate for this defect)
2. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 4.5% of tests (2.66x the national rate for this defect)
3. The aim of a headlamp is not within limits laid down in the requirements, 5.3% of tests (2.24x the national rate for this defect)
4. Emissions levels exceed default limits, 2.7% of tests (7.71x the national rate for this defect)
5. Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc, 2.7% of tests (3.67x the national rate for this defect)
6. A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, 2.1% of tests (1.4x the national rate for this defect)
7. A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 2.1% of tests
8. The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired, 1.4% of tests (1.45x the national rate for this defect)
9. Fuel system leaking, or missing or ineffective filler cap, 1.2% of tests (9.35x the national rate for this defect)
10. Brake hose bulging under pressure, 1.2% of tests (247.54x the national rate for this defect)

From 513 DVSA-tracked Porsche 928 S tests, 2024. DVSA testers marked 1.31% of these flagged Porsche 928 S defects as "dangerous", meaning the tester judged the car unsafe to drive away, against 5.11% nationally.

Most common MOT advisories on a Porsche 928 S

An advisory doesn't fail the car - the tester flags it as worth watching, but it still passes. A different list from the failures above: what testers are noting on a Porsche 928 S before it actually fails on it.

1. A wheel bearing with excessive play, 7.2% of tests (11.11x the national rate for this advisory)
2. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 20.5% of tests (3.68x the national rate for this advisory)
3. A spring or spring component fractured or seriously weakened, 7.4% of tests (1.57x the national rate for this advisory)
4. Significant brake effort recorded with no brake applied indicating a binding brake, 3.1% of tests (1.56x the national rate for this advisory)
5. A tyre seriously damaged, 13.1% of tests
6. A suspension pin, bush or joint excessively worn, 7.2% of tests
7. Tyre tread depth not in accordance with the requirements, 7% of tests
8. Brake disc or drum excessively weakened, insecure or fractured, 3.7% of tests
9. Brake pipe damaged or excessively corroded, 3.3% of tests
10. A brake hose ferrule excessively corroded, 2.7% of tests (2.14x the national rate for this advisory)

From 513 DVSA-tracked Porsche 928 S tests, 2024.

Other Porsche models

• Porsche 911 - 89%
• Porsche Boxster - 84.2%
• Porsche Macan - 92.1%
• Porsche Cayenne - 86.4%
• Porsche Cayman - 89.9%
• Porsche Panamera - 87.8%
• Porsche Taycan 4s 93kwh - 90.8%
• Porsche 944 - 77.4%

Models with a similar pass rate

• Toyota Iq - 81.5%
• Vauxhall Vivaro 2700 Sportive S/S - 81.5%
• Citroen C4 Sense + Puretech S/S - 81.5%
• MG Zs - 81.4%
• Tesla Model 3 Performance Awd - 81.4%
• Jaguar Xjs - 81.4%

If this car is a salvage or write-off

• What does Cat N mean? Category N explained
• What does Cat S mean? Category S explained
• Cat S vs Cat N: the real differences
• Do you need an HPI check on a car you know is a write-off?

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All 2,005 models ranked by MOT pass rate