Here are some articles. There is probably some fact and fiction in each one.
I just find it interesting that in Canada where the weather favors the gas pumping consumer, the oil industry gladly installed the equipment for accurate delivery. Yet they protest the exact same standard be instituted in the United States.....
The reference of Mn and Az was made, but I can't find the specific text. It pointed out that colder states average out better over the course of a year than those of us in the hotter ones.
Hawaii, for instance, had law enacted in 1977 that gasoline delivery be based on 80 degrees instead of 60 like the rest of us. So this concept isn't something new, but the public, and truck drivers especially, no longer want to tolerate it because of the astronomical prices we are already paying.
http://cbs2.com/consumer/local_story_130235459.html
http://abcnews.go.com/WN/Story?id=3355438&page=1
http://abcnews.go.com/GMA/Consumer/story?id=3022167&page=1
http://www.landlinemag.com/todays_news/Daily/2007/Jul07/070907/071307-03.htm