Diesel was always historically far cheaper than gasoline, because its more crude, less refined. Diesel is NOT NOT supposed to be MORE expensive than highly refined gasoline, with a bunch od EPA restrictions and additives in it.
There is only ONE explanation…..The PTB moved some of the poor guy consumer’s gasoline costs onto the wealthier business mans diesel fuel costs. Simple welfare, or smoothing, equality, or call it what you want. Take from the rich and give to the poor.
Another thing they like to do…Is make things they don’t want you to use, COST more. Many homes are heated with Diesel. They want people to change to nat gas. Look at the high price of cigarettes. It’s not natural.