Porsche 928 S Auto (1985)
1985 Porsche 928 S Auto
CarHunch analysed 128 real MOT records for the 1985 Porsche 928 S Auto. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.
This 1985 Porsche 928 S is a reliability disaster by modern standards, with a first-time MOT pass rate of just 2.4% against the UK average of 80%—meaning 97.6% of these cars fail their MOT on the first attempt. The good news is that dangerous defects are rare (0.8% of vehicles), but the sheer frequency of failures makes this a car only for owners prepared for constant, expensive repairs.
At 145,749 miles on average, these 928 S examples have typical mileage for their age, yet they average 0.07 failures per vehicle per test, suggesting the issues are widespread rather than isolated to high-mileage specimens. Before buying one, have an independent Porsche specialist conduct a full pre-purchase inspection and budget generously for transmission, cooling, and electrical work—this is a car that demands deep pockets and mechanical sympathy, not a casual weekend toy.
What to check before buying a 1985 Porsche 928 S Auto
Practical pre-purchase checks for this age and model.
- 📋 Check the full MOT history. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. Enter the reg below for a full AI analysis.
- 🔍 Inspect for corrosion in person. Brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that's expensive to fix and can fail an MOT.
- 🛞 Check tyres and brakes. The most common advisory items at this age. Budget for replacement if they're near the limit — factor this into your offer price.
- 📄 Run an HPI check. The MOT history won't show outstanding finance, insurance write-offs, or stolen status — an HPI check will.
Before you buy a Porsche 928 S Auto
MOT history is one piece of the puzzle. These checks can reveal what CarHunch can't.
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Pass Rate by Fuel Type
| Fuel type | Vehicles | Pass rate | Avg failures |
|---|---|---|---|
| Petrol (99%) | 127 | 2% | 0.06 |
| Other (1%) | 1 | 50% | 1 |
Mileage Distribution
Most 1985 Porsche 928 S Auto vehicles sit in the blue band. If the car you're looking at is outside it, it's either unusually low or high mileage for its age.
Half of all 1985 Porsche 928 S Auto vehicles fall between 116,278 and 138,533 miles.
MOT History Averages
Found a specific Porsche 928 S Auto?
Enter the reg to see its individual MOT history, AI Hunches, and how it compares to this cohort.