Which engine oil ???

[Meir]

Originally Posted by Flavor 987S

Meir, the short answer is, that Porsche is updating their recommended oils list all the time (yearly) for brand and viscosity. So, our Owner's Manuals become out dated in short order. Same is true for recommended service intervals.

good answer.
thanks.

[rem503]

I'm trying 5W-40 Valvoline full synthetic. We drive in spring, summer and fall in northern Ohio. It's on sale at Napa for 5.40 per quart.

[shadrach74]

What flavor said is absolutely true. Also I would add that the XXW number is a measure of of how the oil flows (or doesn't flow) at a 100df. The -XX number is a measure of how oil flows at operating temp 212df. So 10w-40 and 0w-40 perform (read flow) quite differently at 100df, but exactly the same at 212df. My primary concern is start up lubrication. Which almost no oil does adequately.

While I use Blackstone for analysis on several vehicles and enjoy their plain speaking way of explaining each annualized sample, the are still measuring trends.

There is no logical reason I can think of to run 15W multigrade in a water cooled engine with modern tolerances unless those tolerances have widened to such a degree that it is required to maintain pressure. Even if i lived in Phoenix, I'd not be running
15w-XX. At colder temps, much of an oil of heavier XXw is likely pushed right through the bypass.