The average price of diesel dropped for the second consecutive week, the U.S. Energy Information Administration reported.

Diesel fuel still has a large role to play in achieving greater emissions reductions in heavy-duty trucks, experts said during a recent conference in San Francisco. Separately, they urged more in-use testing of engines to verify the gains, and increased use of renewable diesel, which is chemically similar to petroleum diesel, but cleaner.

Florida posted the biggest surge among states in the use of heavy-duty trucks with clean diesel engines in 2017, notching an 81% jump compared with a year earlier, according to data from IHS Markit. This increase came as fleet confidence in the technology took hold and more freight-hauling opportunities opened up in the nation’s fourth-largest state economy, other experts said.

The U.S. average retail price of diesel fell 1.9 cents to $3.220 a gallon while crude prices slipped, according to the weekly report from the U.S. Department of Energy’s Energy Information Administration.

The U.S. average retail price of diesel fuel was virtually flat last week, falling 0.4 cent to $3.239 a gallon, according to the weekly report from the U.S. Department of Energy’s Energy Information Administration.

The U.S. average retail price of diesel fuel fell 2.8 cents to $3.216 a gallon, the fourth week in a row of declines, according to the weekly report from the U.S. Department of Energy’s Energy Information Administration.

The U.S. average retail price of diesel fuel fell 2.2 cents to $3.244 a gallon, the third week in a row of moderate declines, according to the weekly report June 18 from the U.S. Department of Energy’s Energy Information Administration.

The U.S. average retail price of diesel increased for the 10th week in a row, nudging up 1.1 cents to $3.288 a gallon, according to the U.S. Department of Energy’s Energy Information Administration report May 28.

Brazil sank further into chaos May 25 as the fifth day of a nationwide truckers’ strike prompted the deployment of national security forces amid warnings of a calamity in one of world’s largest cities and potentially devastating livestock losses.

A truckers strike in Brazil over higher diesel prices has left at least one McDonald’s in Copacabana struggling to serve its customers. The last perishable food delivery received at the restaurant was May 18, manager Yladian Barbosa told O Globo newspaper.