Why is diesel more expensive than regular gas?

Diesel fuel has been pricier than regular gasoline, with a few exceptions, since 2004

Diesel hasn’t always been more expensive than other gasoline. Then in 2004, a switch happened due to air quality standards, demand, and taxes. In this week’s Indicator newsletter, we dig into diesel prices, what kind of fun people are buying, and other forms of making your tax bill smaller.

(Image credit: David Zalubowski/AP Photo/David Zalubowski)