Hawai'i's wholesale gas prices most likely will rise next week for the first time in about two months after motorists increased their driving and U.S. gasoline supplies declined.

Advertiser calculations show the state may raise the price ceiling by about 5 cents next week if recent wholesale pricing trends continue through today. Gasoline prices could edge higher if crude oil prices continue rising.

The increase would end eight weeks of pricing cuts under the state's gas cap law, which regulates how much wholesalers and distributors can charge. The cap has dropped 90.45 cents since Oct. 16, helped by refinery production being restored after hurricanes Katrina and Rita.

Motorists would likely see the increases beginning next week because prices at the pump have moved in the same direction as the cap, which went into effect on Sept. 1. Drivers yesterday said they liked the declining gasoline prices of recent weeks, but will continue to cut back on their driving.

"I walk and use my bike for short trips now," said Kane'ohe resident Bob Laube, 49, who postponed selling his 4-cylinder Nissan pickup truck when prices rose. "It's better for my health and cheaper."

Hawai'i's has the highest gasoline and diesel retail prices of any state. As of Sunday night a gallon of regular averaged $2.656, or 53.2 cents more than the national average. Hawai'i is the only state where a gallon of diesel costs more than $3.

Prices at Honolulu's least-expensive stations have dropped under $2.50 a gallon, according to Honolulugasprices.com. Even at that level, Pearl City resident Deacon Chun is carefully monitoring how many trips he takes in his 2003 Dodge Ram truck, which he said was getting about 11 miles a gallon. He said he now pays up to $70 to fill up his tank versus $45 when he first purchased the truck two years ago.

Wholesale gasoline prices rose during the past week as the U.S. Department of Energy released a report showing demand for gasoline rose to 9.178 billion barrels a day from 9.162 a year earlier. That led to speculation that a growing U.S. economy will boost fuel consumption further.

The department also released figures showing U.S. gasoline stockpiles were lower than a year earlier. Cold weather in the Northeast also contributed to traders bidding up crude oil to a one-month high.

"The cold weather is moving into the Northeast and that's going to push prices higher," said Mike Sander, an oil broker at Altavest Worldwide Trading Inc. in Laguna Hills, Calif. "We could see crude oil go to $62.50 in a week or so."

Oil prices spiked above $60 a barrel yesterday amid reports that a snowstorm would hit the U.S. Northeast, the world's largest heating fuel market, and boost demand for crude oil and natural gas.

Chun, the Pearl City resident, said he was glad to see the prices decline under the cap, yet knew prices could go up again.

"As long as it doesn't go up like before," said Chun, who considered buying a hybrid truck when gas prices topped $3.50 a gallon in September.

Hawai'i's gas cap is based on five days of wholesale price data from three Mainland markets. The Advertiser's preliminary calculation of next week's gas cap is based on the first four days of the five-day period.

The Advertiser uses prices from Bloomberg News while the state uses figures supplied by the Oil Price Information Service. The difference in data sources can result in an estimate that is a few cents different than what the state announces.

Reach Greg Wiles at gwiles@honoluluadvertiser.com.