Mistake one: mileage-based oil thinking
Porsches want an annual oil service regardless of miles. Oil degrades by time as well as distance — moisture, fuel dilution, additive breakdown — and a garaged 911 driven 2,000 gentle miles a year is not exempt. Annual service is the cheapest thing you will ever do for a flat-six.
Mistake two: believing “lifetime” fluids
PDK fluid is not lifetime. Neither is coolant, brake fluid, or differential oil. “Lifetime” means the design life of the warranty. A PDK service costs a fraction of the transmission it protects, and the difference in shift quality afterward tells you everything.
Mistake three: the wrong oil spec
A correct viscosity with the wrong approval is still the wrong oil. Porsche’s A40 approval exists for a reason; bargain-bin 5W-40 does not meet it. We stock to the approval, not just the number on the cap.
Mistake four: ignoring the sounds
Cold-start rattles, ticks that change with RPM, smoke on startup — on certain generations these are early bore-scoring and tensioner conversations, and early is when they’re affordable. A borescope during routine service is cheap reconnaissance.
Mistake five: buying without a PPI
The most expensive Porsche mistake happens before ownership begins. A pre-purchase inspection with compression, borescope, and over-rev report costs a fraction of what one hidden problem swings the deal by.