Mobil 1: Mixing Viscosities = ?

[Doug H]

Hello Rich,
0w-40 lubricants have been available for well over a decade now and no 15w-50 engine lubricant has been Approved by Porsche since a little before 1999

The first synthetic lubricant factory filled by Porsche was a 10w-30 (1992) which was dicontinued in favor of a 5w-40 (1993). 0w-40 and 5w-40 viscosities have been the factory fill since then (with very few exceptions)

Of course one can use any engine lubricant they wish

Regards
Doug