First and foremost, i am no oil expert. But i will give my understanding of the oil situation down here.
If you re-read my post, you will notice that I did point out that the Mobil "Truck and SUV" oil is available at the local Fleet Farms. It has an API rating of CI-4 which is the current API rating for diesel oils. It is essentially Mobil Delvac 1 repackaged, just like the Caterpillar synthetic oil. Delvac 1 also carries a boat load of endorsements on thier web page from diesel engine OEMS.
I also checked the Mobile web page for the Mobil 1 0W40. The 0W40 oil has a whole stack of "S" ratings, and a CF rating, which is out of date when it comes to diesel applications. Unlike the Delvac 1 page on the Mobil web, the 0W40 carries no diesel OEM endorsements.
So I'll let you folks make your own decision if the Mobile 1 0W40 is an appropriate oil to use here in the states.
As far as approaching vendors to obtain oil, here is what I've done.
Also, i don't want to buy in bulk and ware house oil. I'm just a guy that has a few diesel powered vehicles for my own amusment.
Walmart used to carry Mobil Delvac 1. About a year ago, it was out of stock. I asked the store manager when it would be in and he said he'd check and give me a call. He called back and said that they were having availability problems, and didn't know if they would ever get it again.
I went to NAPA to see if they would order a case of Delvac 1. The store manager said one case wasn't worth the effort.
Wondered into Fleet Farm. There on the shelf was Mobile Truck and SUV 5W40 oil. Low and behold, on the back in the API rating, was the coveted CI-4 rating. Problem solved. I get all my Diesel oil at Fleet Farm now. its packaged in a convienant six pack. 5 in the pan, and one to top off later, and I'm a happy camper.
I've been keeping an eye on Walmarts offering. The Rotella 5W40 is occasionally in stock. Not often enough to depend on. I used to run the Rotella synthetic, but it seemed to make all the rubber stuff that comes in contact with the oil turn rock hard. Delvac 1, and Mobile 1 Truck and SUV have not returned to the shelf yet.