All generations and engines together · 22,079 MOT tests in the 2025 data · typical mileage at age 7: 24k
Split by first-registration year. Cars registered in a changeover year can belong to either generation.
Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.
Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.
The rows that judge the model rather than its keeper. 7,549 tests in this band.
Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.
Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.
The intermediate shaft bearing in the M96 flat-six can break up and starve the engine of oil, wrecking it with no warning, sometimes at low mileage. It mainly hit 1997-2005 996 cars and early 997.1s built before mid-2005; GT3, Turbo and GT2 models use a different engine and are not affected. It was serious enough to trigger a US class action (Eisen v Porsche), which Porsche settled in 2013, and later cars got a redesigned, non-serviceable bearing. A retrofit upgrade and oil analysis can catch it before it lets go; full engine replacement runs well into four figures.
Some M96/M97 engines with Lokasil-coated cylinder bores develop deep scratching on the bore walls, letting oil and coolant mix and pushing up oil consumption and piston noise. It's linked to a casting problem Porsche partly addressed by re-sleeving affected blocks on the production line, but there was never a public recall or fix for cars already sold. It shows up anywhere from a few thousand miles to well over 50,000, and a full rebuild or replacement engine is a five-figure job.
The original rear main seal on 996-era engines can weep oil past the crank flange, leaving drips under the bellhousing and a constantly topped-up oil level. Porsche redesigned it with a PTFE seal that became standard fit, and it's a routine job for a specialist to swap while other engine work is being done. Left alone for years it just means oil loss and mess rather than sudden failure, but it's worth budgeting a few hundred pounds to have it done properly.
Early 991-generation GT3s built in late 2013 suffered a small number of engine fires linked to a connecting rod bolt issue, and Porsche halted GT3 deliveries in January 2014 before recalling around 785 cars worldwide to replace the engine free of charge. It doesn't touch any other 991 variant, so a standard Carrera, S or Cabriolet from this era isn't affected.
This model's measured MOT signature is essentially none recorded, no dominant advisory or fail pattern shows up in the test data. That's real, but it's mostly because the MOT test doesn't look inside an engine: IMS bearing failure and bore scoring are the two big-money 911 problems, and neither one throws up a warning light or an advisory before it happens. A clean MOT sheet on an older 996 or early 997 tells you the tyres, brakes and lights are fine; it tells you nothing about the bottom end.
Built from the two sections above.
Same segment (Coupés, convertibles & GT), best MOT record first. Compare before you shortlist.
Head to head with the other popular cars in its class on reliability and common faults.