Oil consumption is a very emotive issue, especially given the claims of major manufacturers. However over the years I've been playing with cars, oil consumption has dropped significantly as a result of better machining and honing of cylinder bores, as well as better lubricants, and cleaner air intake systems.
Clearly on the 997 with its electronic measurement, while you need to measure when its hot, and idling, you can put the oil in later cold. In winter it perhaps would be better to leave the oil inside the house, rather than in a frozen shed for topping up, to counter the oil expansion with warmth .
Sudden changes in oil consumption on the 997 need careful checking. Yes you need to go through the level ground scenario, and at operating temperature etc.
However 1.25 litres of oil in 3K miles needs investigating.
We are aware of a larger number than expected 997 Gen 1 Standard Engines have been affected by the erosion of the Nikasil Coating particularly on no 6 Bore, taking the geometry out of shape leading to increased oil consumption, loss of compression, and piston slap, and possibly a partial siezure because of pick up between the piston/rings and the parent alluminium casting of the cylinder bore.
The tell tale is usually higher oily deposits on one Exhaust Bank.
Clearly there are many other causes for oil consumption. Problems with Air Oil Separator, Valve Guides and Seals, and general wear. These may not need major work, anbd you will have to top up a bit more.
However if in doubt get the car into your OPC or Indy and get them to do a Endoscopic Examination of the Cylinder Bores through the Spark Plug Holes. If there is signs of Nikasil Erosion, this check will identify it before a major development or failure.
Best Regards Big Bob :bye:
