The U.S. average retail price of diesel dropped 3.5 cents to $2.489 a gallon, while the stubborn glut of crude caused oil prices to tumble to about $43 a barrel — a range last seen in early August — and into a bear market, experts said.

The U.S. average retail price of diesel dropped 4 cents to $2.524 a gallon, while crude oil prices remained below $47 a barrel.

U.S. diesel and gasoline prices each made modest moves during the week ended June 5 but in different directions. Diesel slipped 0.7 cent a gallon and gas rose 0.8 cent, while crude oil dropped toward this year’s low point below $46 a barrel.

Along with increasing its diesel tax by 10 cents, Indiana recently approved a 10-cent increase to a surcharge tax for trucks.

INDIANAPOLIS — Diesel fuel dominates the commercial truck world today and will continue to do so in the near future, but greenhouse gas regulations will force the industry to use it more efficiently and eventually could push fleets toward other, cleaner fuels, industry executives said here at the Green Truck Summit.

The newest heavy-duty truck set to operate at the Port of Los Angeles emits an unusual byproduct that California could certainly use more of: water.

Oklahoma and Alaska are about as red as states can be. Oklahoma has only elected Republicans to the Senate going back to 1994. Republican Don Young has been Alaska’s only congressman since 1973. However, both states are considering raising fuel-tax rates for the first time since the 1980s.

Oklahoma’s tax on gas and diesel would increase under a budget proposal Gov. Mary Fallin (R) presented to legislators this week.

With the contentious 2016 election over and few officials on the ballot again until 2018, transportation stakeholders believe that the current state legislative sessions could see fuel taxes raised to cover large funding shortfalls. Only New Jersey, which has off-year elections, did so in 2016.