I just heard that Mobile one synthetic tranny oil 75-90w is not good for the tranny. Although it has a GL-5 rating which exceeds the Mopar GL-4 specs, it doesn't contain the additives for yellow metal which inhibits the corrosion for those parts. Has anyone heard of this? Is anybody using this oil? Is there any oil better than the Mopar oil which is the Castrol Syntorque?