Used car guide

1991 Porsche 911: common problems and MOT failures

What MOT testers find on the Porsche 911 first registered in 1991: we looked at the 873 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

873MOTs of 1991 cars, done in 2023–2025
87%pass first time (all 1991 cars: 71%)
2,800typical miles a year
12%had oil and fluid leaks flagged

Common 1991 Porsche 911 MOT failures and advisories

The share of 1991 Porsche 911 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Oil and fluid leaks
    12% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

  • Lights and electrics
    11% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Tyres
    9% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Suspension
    7% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

  • Brakes
    5% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Wipers, windscreen and mirrors
    4% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

Questions to ask the seller before buying a 1991 Porsche 911

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Can I see the service history and receipts for any big jobs?

Looking at a Porsche 911?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Porsche 911 compared

YearMOT testsMost flagged
2026–Too new for MOT data
2025–Too new for MOT data
2024–Too new for MOT data
2023–Too new for MOT data
20222,632Tyres 11%
20213,295Tyres 12%
20204,568Tyres 14%
20196,900Tyres 16%
20186,387Tyres 14%
20175,621Tyres 15%
20165,065Tyres 15%
20155,104Tyres 14%
20144,622Tyres 14%
20133,806Tyres 15%
20124,587Tyres 15%
20113,805Tyres 13%
20105,111Tyres 15%
20094,336Tyres 15%
20085,492Tyres 16%
20077,246Tyres 16%
20068,246Brakes 19%
20058,289Brakes 21%
20047,193Brakes 20%
20037,717Brakes 22%
20027,069Brakes 22%
20014,416Brakes 24%
20002,714Brakes 26%
19993,564Brakes 23%
19983,013Brakes 23%
19972,134Oil and fluid leaks 11%
19962,794Oil and fluid leaks 11%
19951,911Oil and fluid leaks 14%
19941,538Oil and fluid leaks 13%
1993769Oil and fluid leaks 12%
1992609Oil and fluid leaks 11%
19902,014Oil and fluid leaks 15%
1989–Too few tests
1988–Too few tests
1987–Too few tests
1986–Too few tests
1985–Too few tests
1984–Too few tests
1983–Too few tests
1982–Too few tests
1981–Too few tests
1980–Too few tests
1979–Too few tests
1978–Too few tests
1977–Too few tests
1976–Too few tests
1975–Too few tests
1974–Too few tests
1973–Too few tests
1972–Too few tests
1971–Too few tests
1970–Too few tests
1969–Too few tests
1968–Too few tests
1967–Too few tests

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Porsche 911 cars first registered in 1991. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score