Interesting.
Around here, diesel is usually 50 to 60 cents higher than the advertised price for unleaded regular gasoline. Regular (85.5 octane) is running about $3.199 right now, diesel is about $3.699.
By the way, I just checked gaspricewatch.com, and they are WRONG! Totally, completely, across the board WRONG! They say their prices were updated an hour ago. They also say the price of regular varies from $3.02 to $3.11. THAT is funny! Gas and diesel prices around town rarely vary more than a cent or two, 4 cents at the most, unless they are going up or down. The price for regular just jumped from $3.099 up to the current $3.199 last week.
EDIT: On the way to town tonight, I noticed that the Cenex stations had jumped to $3.259, so I stopped on the way home and filled up at the Holiday station. It was still $3.199 there, $3.229 for mid-grade.
Diesel, IIRC, is a little over $4.