Originally Posted by treoless
What do you guys think of Pennzoil Ultra? According to some guys on BITOG, oil vapor is the major cause of intake valve deposits in DI engines and a low volatility oil is recommended. Pennzoil Ultra 5W-20 seems to have the lowest Noack Volatility - 5.0% (Amsoil Signature is 5.7%)
Some think Ultra's reported Noack value is too good to be true given it evidently still uses a fair amount of Group III (super-refined conventional) base oil. On the other hand, these are the values Pennzoil has reported and confirmed.
I'm using Ultra in my Focus because of the low reported Noack. Even if the volatility numbers are wrong, it's still a great oil. Hard to see how one could go wrong.