Shell Rotella T6 - safe on boxster?
 

Saw them at US Walmart ... $21 for 4 qrt, close to 40% cheaper than Amsoil. :barf:

I am a total neophyte as far as Porsche cars go, but I do know a lot about oil. Rosella T Dino as well as synthetic are especially formulated for Diesel engines. The two most prominent differences for diesel use are ZDDP additive and additional detergents.

ZDDP is sometimes called zinc additive and is basically a sacrificial metal for the extreme pressures in flat tappet engines. Flat tappets are found in many Diesel engines but not in your Porsche. This also makes this oil good for old cars built before the widespread use of roller cam followers.

The added detergents which are absolutely necessary for Diesel engines for the purpose of soot dispersal are certainly not necessary for your Porsche.

I have read a little about the oil needs for your Porsche, but am totally unqualified to make a recommendation which oil you SHOULD use, but I feel confident in reccomending this oil as one that you should NOT use.

Doc