Porsche 928 s
Reliability, running costs, and MOT data across 3 years from 364 real MOT tests.
Avg Pass Rate
79%
Total Tests
364
Best Year
1990 (84%)
Years Covered
3
How reliable is the Porsche 928 s?
Porsche 928 s by Year
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About the Porsche 928 s
The Porsche 928 s has been tested 364 times in 2024 MOT data across 3 model years (1990 to 1992), with an average pass rate of 79%. That's close to the national average of 82%. Available as petrol.
Best and Worst Years
The 1990 model is the most reliable with a 84% pass rate from 125 tests. The 1992 model has the lowest at 72%. The 12 point spread between years means reliability varies somewhat, but no year is dramatically different.
Reliability Trend
Older PORSCHE 928 Ss tend to have better MOT pass rates than newer ones, with an average decline of 8 percentage points across model years.
Mileage Across Years
The oldest model in our data (1990) averages 115,960 miles, while the newest (1992) averages 118,583 miles. Older models have covered serious mileage, so suspension and drivetrain wear are worth checking.
Compared to the Porsche brand average of 92%, the 928 s is 13 points lower, placing it among the less reliable Porsche models.
Click any year in the table above to see detailed running costs, individual reliability data, and comparisons with similar cars.