Porsche 911

991.1 (2012–2016)

9A1 flat-six · 3.4 L / 3.8 L NA (2012–2016)

Oil Specification

Grade

Mobil 1 0W-40 or Porsche Classic Motor Oil

Capacity

8.75 L (with filter)

Porsche Spec

Porsche A40

Service Schedule

Engine oil & filter

1 year / 12,000 miles

Brake fluid flush

2 years (regardless of mileage)

Auxiliary drive belt

8 years / 80,000 miles

Pollen filter

2 years

Air filter

4 years / 40,000 miles

Spark plugs

4 years / 40,000 miles

Coolant flush

4 years, then every 2 years

PDK fluid

4 years / 40,000 miles

Front strut top mounts

Common wear point on 991

Inspect at 60,000 miles

Safety-critical / commonly missed

Known Issues & Watch Points

Bore scoring (9A1 — significant risk)

Critical

The 9A1 flat-six in 991.1 models has a well-documented bore scoring problem. Cylinder wall wear caused by oil film breakdown at high RPM leads to excessive oil consumption and eventually engine failure. Risk is higher on track-used cars and those regularly taken to the red line. A bore scope inspection is essential before purchase on any 991.1.

High oil consumption

Important

Closely related to bore scoring — 991.1 engines consuming more than 0.5 L per 1,000 miles should be investigated. Check oil level at every fuel stop and track consumption trend carefully.

Coolant pipe failure

Watch

Plastic coolant pipes and the coolant expansion tank can crack with age. Inspect at every service and replace proactively if signs of weeping or crazed plastic are visible.

Intervals are general guidance. Always refer to your car's Maintenance Booklet and consult a qualified Porsche specialist. Known issues are documented based on commonly reported patterns — not every car will be affected.

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