I've been using Mobil1 Advanced Fuel economy for a long time in various types of vehicles. I currently run it in my 4R, 0W20 as recommended. When I got the 4R from new, I drove on its original oil and changed it out at 1,865kms just to get rid of the oil they put in from factory and to clear up any deposits.
The dealer did tell me that they do start up the engines at the factory, make sure its all well, and then replace the oil again before shipping out the truck. So basically I didn't have to change it so soon, but piece of mind and I plan to run this truck for a longgggg time. Going forward I think I'll change it every 5-6000kms or so, see in what condition it's in at that point.