Gas prices edge all-time worst in Orange County

The cost of an average regular gallon of gasoline in Orange County rose to $3.579, narrowly beating the mark of $3.574 set Tuesday.

The per-gallon cost of mid-level and premium gasoline and diesel fuel rose to $3.81, $3.872 and $4.217, respectively.

Orange County gas prices have reached record levels more than once this year, although the prices had dropped slightly before surging again this week.

Marie Montgomery, an Automobile Club of Southern California spokeswoman, couldn’t say exactly why the costs were up again, but said one factor might be that refineries are starting to produce summer-blend gasoline, which causes less pollution and costs more to make than the winter blend.

— Michael Miller