On a federal level, diesel has a higher tax rate than gasoline; the tax per gallon is $0.184 for gasoline and $0.244 for diesel. State taxes vary but are closer in price.
In the United States, the vast majority of passenger vehicles run on gasoline, while large commercial trucks typically run on diesel. As a result, the federal government taxes diesel fuel more heavily to recover more money from the transportation industry to help cover the cost of road maintenance and repair. People who drive diesel-powered passenger vehicles pay this extra tax as well, which has slowed the growth of the diesel market in the United States, according to Business Insider.