Rotella T 15w40 is good. Have also run it for years with no trouble. Ran it in some older DT400 series engines without any trouble. 9000+hours and the cam and crank neither one were ever out of the block.
I went through this situation years ago with buying brand name oils and machinery company oils. I did an indepth study, got all the company specks on the oils and made the decision to go with Case IH oil!!! Yes it is true all oils whether it is TEXACO, ESSO, JOHN DEERE, NEW HOllAND, are all derived from the same base stock oils, oil is oil. But the oils you buy to put in your tractor are not the same. Different companies take these base stock oils and add different additives to make a particuliar oil just for the application it is to be used for. Additives for oxidation, friction, detergents, the list goes on and on are added in different degrees to make up the oils. The more additives you add to the oil the more the costs go up. All the major companies handle fleet oils that they sell for the trucking industries that they say are suitable for agricultural purposes and are reasonably priced. If you are a penny pincher then go with the ESSO, TEXACO, SHEll brands, they will work, but if you really care about your engines and want the very best protection for them, go with the manufacturers oil. THE FACTS--- trucking fleet oils are made for the trucking industry specifications. Trucks running 60 mph, 1300 rpm for hrs on end with a clean air supply, whereas a farm tractor pulling at 2100 rpm under extreme load where it is lugged down 500rpm at a time and is running in a cloud of dust aren't the same conditions by any means. If one checks with his oil supplier he will find he also can sell you an EXTREME SERVICE oil, but it will cost more money. Farming and construction are considered extreme service conditions and engines working in these conditions should be using oils capable of the task. These truck fleet oils will do the job, but manufacturers specked oils will do a much better job under agricultural and construction conditions. If one has to stretch an oil interval change a few more hours over the recommended period it is better to have the manufactures' specked oil in there. I use Case IH 15w 40 oil in every thing on my farm including my wife's explorer. I buy it in bulk from my dealer, he fills my drums over and over.
As a former user of Casen1, I am glad we quit using it. I know alot of people will swear by it, but the oil created an oil consumption problem for us. We tried using it in a semi truck we purchased and oil consumption immediately went dramatically up. We started using Rotella 15-40 and it took care of the problem. Also noticed that oil consumption went down on other engines that may have required a quart here and there. I am not the only one to have had this occur with Case oil. There have been previous posts on here stating the same thing.
Consider Cat oil. It's my understanding they take the best oil (by Mobil I think, not synthetic) and add one or two more additives per Cat's specs. I think you'll find it's competively priced and very good oil.