I have not been able to find any premium diesel in the area. I drive through (Grand Rapids to Mack City) so don't live there and can't claim I've checked every station.

As you probably know, Michigan has no requirement that the cetane be posted (unlike octane, which is posted for all grades) and no definition of what makes diesel "premium." And most station attendants are clueless if you ask about the cetane level or whether it's "premium" or not.

Meijer lists all their diesel as "premium," but no one has been able to tell me what that means. There are several Shell stations (one in Muskegon and one in Ludington) that sell two grades of diesel, and I presume that the more expensive grade is better, but again I've never been able to find out the actual cetane rating.

I haven't seen premium at any Amoco station in the area, but there may be one.

If you find out differently, please let us know.