The national average price for a gallon of diesel collapsed for the first time in eight weeks, according to the Energy Information Administration. For the week ending May 21 prices fell 3.2 cents to $2.888, ending a seven-week run-up of 35.5 cents since the week ending March 26.

All regions reported a price drop but the most dramatic was seen in the Rocky Mountain region, down one nickel to $3.024. Prices held the steadiest in the region that once again retains its claim to the most expensive place to buy diesel—California. There, prices fell a modest 0.8 cents to $3.234. Bargain hunters are more apt to fill up in the Gulf Coast region once again, where prices were $2.801 after a 2.8-cent slide.

For more detailed diesel price information, go to www.fleetowner.com/diesel.xls.