If you go to "Flying J.com" & click on the "gasoline" pricing, it will show you all gasoline, propane & auto-diesel pricing for their stations in the US & Canada.
If you click on the "diesel" pricing, it will show you prices that the big trucks have to pay. Here in AZ, auto-diesel is 8 cents cheaper than the big truck diesel. The "gasoline" pricing forum will show that discount, if it applies to the area you are buying from.
It's amazing the price differences throughout North America ( including Canada). Washington State, Spokane & Ellensburg are extremely high. Must be higher state taxation. However, Tacoma is usually quite a bit cheaper.
The other day, I heard about a station selling reg. gas for $2. 05/9 in Iowa.
Parts of OK. used to be very reasonable until a recent fuel tax hike. Used to love to fill-up in the OKC Flying-J. It was, always, much cheaper than the AZ. area. Now, it's sometimes more expensive than the Phoenix Flying-J.
Joe F. (Buffalo)