hey im a newb to this message board as well as a diesel engine. i just got my truck about a week ago and im still learning. the first time i got fuel i got some "master" by mistake cause i didnt know there was a difference. so the next time at the same store i got the "auto" diesel and the truck doesnt perform the same or get as good of mpg. in the manual it says to run a #2 diesel and thats what the master was, the auto diesel didnt say. the store has 3 different pumps. auto, master, and sattelite. which one do i need to run?

Most run #2 diesel in the summer and in warm climates because it has a higher BTU value and gets better mileage. In colder places they switch to #1 in the winter because it has a lower gel point. Get #2 if you can and use a good additive such as Power Service white bottle.

The other names you gave are probably trade names for the uninformed car diesel drivers. Stay away from them since you don't know what you're getting.

Edwin