Thanks for the replies!

I have already done an oil change using Castrol Synthetic. I've always used mobil1 in the past but the cap said Castrol so I went with that.

I am very used to drive by wire. I was involved in Nissan Titan programmer development and one of the first things we tuned was the DBW. I would say that my X5 is a fairly aggressive tune. It could just be that way from the factory though. My wife doesn't even like to drive it. She says its too jumpy.

Thanks again for the replies!