The state Public Utilities Commission may increase next week's wholesale gas cap by about 6 cents a gallon when it announces a new price ceiling today that will take effect Monday.

Advertiser calculations show the state will raise the cap for a second consecutive week after crude oil reached a five-week high. The increase will be the second consecutive week the cap has risen.

Hawai'i's gas cap is computed using wholesale prices over a five-day period in New York, the Gulf Coast and Los Angeles. It regulates the wholesale prices and leaves retailers free to set pump prices.

As of last night a gallon of regular gasoline averaged $2.64 statewide, the highest in the country. The national average was $2.18.

The average price of diesel, which isn't covered by the gas cap law, was $3.318 a gallon in Hawai'i versus $2.55 a gallon nationally.

State tax data shows motorists bought 3.29 million gallons of diesel in October, an 8.8 percent decline from a year earlier.

The Advertiser's price projection is based on market data provided by Bloomberg News. The state uses Oil Price Information Service for its computations.

Because of the different data sources the estimate may differ by a few cents from the state's.