PORSCHE 928 S (1991)
Running costs, common problems, and reliability data based on 181 real MOT tests in 2024.
MOT Pass Rate
81%
Total Tests (2024)
181
Avg Mileage
114,141 mi
Est. Annual Cost
£2,247
Is the 1991 PORSCHE 928 S reliable?
Good reliability. Occasional issues but generally solid. That's close to the national average of 82%. It falls below the PORSCHE brand average of 92%.
At 33 years old, 81% of PORSCHE 928 Ss from 1991 passed their MOT first time in 2024. That's based on 181 tests across the UK. The average mileage at this age is 114,141 miles.
How does the 1991 PORSCHE 928 S compare?
Mileage Analysis
The average 1991 PORSCHE 928 S has 114,141 miles on the clock, which is significantly below the expected 244,200 miles for a 33-year-old car. Low-mileage examples may have spent time sitting unused, so check for issues like corroded brakes or perished rubber seals.
Best year to buy a PORSCHE 928 S?
The most reliable year is the 1990 model with a 84% MOT pass rate, while the 1992 model has the lowest at 72%. The 1991 sits between the two at 81%.
How much does a 1991 PORSCHE 928 S cost to run?
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT pass rate data. Insurance not included.
PORSCHE 928 S by Year
Checking a specific PORSCHE 928 S?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 1991 PORSCHE 928 S
The 1991 PORSCHE 928 S is a luxury with a 4957cc petrol engine. 181 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. Among all cars from 1991, the average MOT pass rate is 78%, and this model beats that benchmark.
With an average of 114,141 miles at 33 years old, PORSCHE 928 S owners tend to use this car less than the typical driver. Very low mileage could mean the car has been garaged or used only for short trips, which can cause its own issues like battery drain and moisture buildup.
1991 PORSCHE 928 S Fuel Costs
The 4957cc petrol engine is on the larger side, so fuel won't be this car's strong point. Expect around 30 mpg in mixed driving, which works out to roughly £1,592 per year at current petrol prices of 142p per litre (based on 7,400 miles per year).
What does it cost to own a 1991 PORSCHE 928 S?
Total estimated annual running cost is £2,247 (£187/month), broken down as £1592 fuel, £250 road tax, £55 MOT, and £350 predicted repairs. Repair costs are moderate, reflecting the 81% pass rate. Keeping on top of servicing will help avoid surprises.
PORSCHE 928 S 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.
Buying a Used 1991 PORSCHE 928 S
At 33 years old, the PORSCHE 928 S is firmly in budget territory. Purchase prices are low, but check for rust, worn suspension bushes, and electrical gremlins. A full service history is especially valuable at this age. If you're flexible on year, the 1990 model has the highest pass rate at 84%.
Alternatives to the 1991 PORSCHE 928 S
If reliability is your priority, there are 4 similar cars with a higher MOT pass rate. Here are comparable petrol cars with similar engines:
- JAGUAR XJS (1990) 82% pass rate (+1%) from 1,011 tests
- MERCEDES 500 (1991) 87% pass rate (+6%) from 356 tests
- MERCEDES SL (1991) 86% pass rate (+5%) from 288 tests
- JAGUAR XJ (1990) 86% pass rate (+5%) from 282 tests