Hawai'i drivers will feel Hurricane Rita's impact next week as gasoline prices under the state's new wholesale price cap are likely to rise by as much as 27 cents a gallon.

The rise in prices starts Monday — and that gives drivers an incentive to fill up this week and try to avoid buying gas next week.

"If the price is going up, then I know I'm going to fill up, definitely," said Ryan Tokumura, an associate at an actuarial firm. Tokumura said he coaxes mileage out of his 1998 Toyota Forerunner in weeks when prices are high and fills up in weeks when prices go down.

Since Sept. 1, when the nation's only gasoline price cap took effect, Hawai'i has seen weekly swings of as much as 50 cents a gallon at the pump.

Each Monday, the state adjusts the maximum price that wholesalers can charge for gasoline, based on an average of prices in Los Angeles, along the Gulf Coast and in New York. Next week's cap will be announced today.

According to Advertiser calculations, the cap for regular on O'ahu is likely to be set at about $2.59 as of Monday, up from $2.32 this week. That number is before taxes and retail markup. Prices at the pump will likely be $3.33 or more starting Monday.

According to Democrats' calculations released yesterday, the increase will be 25 cents a gallon.

The price increase at the pump may be less than the full 27 cents because some retailers have not lowered prices this week in line with the drop in the wholesale cap from the previous week.

The wholesale cap this week of $2.32 would suggest a price at the pump of $3.06. That includes 62 cents in taxes and an estimated 12-cent retail markup.

The average price at the pump in Honolulu for a gallon of regular was $3.246, according to yesterday's AAA Daily Fuel Gauge Report.

Jack Suyderhoud, a business economics professor at the University of Hawai'i-Manoa, said Hawai'i gas stations may keep prices high for the rest of this week to offset the potential loss in sales next week when the cap goes higher.

"I think retailers won't drop prices as much this week because they know nobody will come in next week," Suyderhoud said. "A 20-cent difference is a big enough amount that's going to catch consumers' eyes.

"Consumers will fill up this week," he said. "And try not to fill up next week."

Gas prices have risen following hurricanes Rita and Katrina, which left about a dozen refineries in Texas and Louisiana closed yesterday.

"We expected gas prices to rise next week due to the effects of Hurricane Rita," said House Majority Leader Marcus Oshiro, D-39th (Wahiawa). "It's positive that consumers are now shopping around for the best prices and timing their purchases now that we can anticipate trends."

Drivers across the United States are seeing higher prices at the pump, and analysts say that won't change anytime soon. At an average of $2.81, the U.S. retail price of a gallon of gasoline is more than 20 cents higher than a month ago, before Hurricane Katrina struck the Gulf Coast.

Reach Sean Hao at shao@honoluluadvertiser.com and Dan Nakaso at dnakaso@honoluluadvertiser.com.