The average price for a gallon of diesel went up 0.6 cents to average $2.348, according to the Energy Information Administration. The overall increase was driven by a sharp ramp-up in prices in the West Coast region that offset stable prices in all other regions.

California, which had already been averaging record highs, saw the worst of the price hike, up 7.9 cents to $2.657. The West Coast saw the second-highest upswing in prices at 6.4 cents to $2.594, followed by a dramatically milder 1.6-cent hike in the Rocky Mountain to $2.421.

New England saw the largest price break, falling two cents to $2.488. The cheapest region in which to fill up is the Gulf Coast at $2.279 after a 0.1-cent rise.

For more detailed information on diesel prices, go to www.fleetowner.com/diesel072505.xls.