Greetings from Australia.
I have a 1993 968 CS. The motor is a Porsche exchange replacement with only about 3k miles on it.
Anyway, I recently changed from a Castrol 15W 40 Blend mineral oil to a Brad Penn 20W 50 green oil (ZDDP in it, recommended etc...)
Anyway, there seems to be a mild black sheen on my rear bumper now, just above the exhaust tip, which I have noticed since using Brad Penn.
Could this be related to the Brad Penn oil and a side effect from the ZDDP through the Catylitic converter? or a faulty O2 sensor caused by this type of oil?
Or completely un-related?
I am going to drain the oil and have it analysed next week and re fill with Castrol synthetic 10W 60 (Hot summers here
)
I have always used castrol products but could see the benefit of ZDDP oils as well for Porsches of this vintage.... however Brad Penn have advised to me that its the wrong oil and I should be using a modern synthetic or a mineral like I had in previously with more frequent changes(car gets
driven hard)
Any commentary would be much appreciated:
