Day one of Hawai'i's experiment with gasoline price controls saw barely a budge in pump prices and no significant supply problems.

Even with the nation's only legal limit on gasoline prices, many Honolulu stations continued to sell gas for the same price as the day before the cap.

"It looks like a normal day," said Barney Robinson, who operates Chevron stations near Hono-lulu International Airport and in Kahala, where the price for regular was unchanged at $2.96.

The biggest impact appeared to be drivers filling up in anticipation of higher prices next week when the cap is adjusted to reflect the recent rise in prices on the Mainland.

Hawai'i's Democrat-dominated Legislature adopted the gas cap to bring prices, which have often been the highest in the nation, in line with Mainland prices. The timing couldn't have been worse, however, with Hurricane Katrina forcing Mainland prices to record highs.

When the gas cap undergoes its first adjustment on Monday, the ceiling on wholesale prices will rise by about 27 cents.

"Usually I don't top it off, but I figured it was going to go up by Monday," said Dyan Kleckner of Makiki, as she pumped 8.8 gallons yesterday — at a cost of $25.50 — into her 2003 Subaru Forester. "Not that it'll make a difference, because I'm going to have to fill up again eventually."

Despite slightly higher demand, there were no major supply problems reported yesterday.

Robinson, the Chevron operator, said demand was normal yesterday, but he remained concerned about a possible jump in demand this weekend.

"Everybody is aware that prices Monday are going up," he said. "So everybody will try to fill up before Monday. If we get a huge run, well, yeah, we may be low on product."

Jean-Denis St. Onge was focused on next week's possible rise in prices when he stopped at Iwilei Costco yesterday to fill his Nissan Frontier truck. St. Onge, 35, sat in a line of more than 20 cars "because gas is going to go up in a couple of days. I thought I better fill up for the weekend."

Any significant change in gasoline buying habits could result in distribution problems and gasoline shortages, said Bill Green, a former owner and now consultant to the Kahala Shell gasoline station.

"If there is a shortage, it's because people are filling up and keeping their tanks full," he said. "That could overwhelm the system."

That cap is set once a week based on wholesale prices in Los Angeles, the Gulf Coast and New York. Before the cap, Hawai'i prices were generally based on Asian and Alaskan crude oil and gasoline costs. The caps don't require wholesalers to price at the maximum allowed, but economists and oil industry analysts said it is likely they will to offset times when they are forced to lower prices.

On Wednesday, Gov. Linda Lingle urged local refiners Chevron Corp. and Tesoro Petroleum Corp. not to charge Monday's maximum wholesale price of $3.04 on O'ahu, including taxes, because the gasoline they will sell next week was bought at pre-Katrina prices. Neither Chevron nor Tesoro will discuss what prices they will charge next week.

"It's impossible for us to know what will happen and what the response from consumers will be," said Chevron spokesman Albert Chee.

Lingle, who opposes the caps, has the power to suspend them if conditions warrant. Her spokesman, Russell Pang, said nothing happened yesterday that would cause her to suspend the law.

The fact that local gasoline prices did not fall yesterday does not mean the law is a failure, said House Majority Leader Marcus Oshiro, D-39th (Wahiawa).

"If people expect prices to come down because the law is in effect today, that's a mistake," he said. "The purpose of the law is to make Hawai'i prices track the price of oil on a national basis.

"When those prices drop, so should our prices in Hawai'i."

For now, Mainland prices show no signs of dropping. In fact, given continued high prices for wholesale gasoline in Los Angeles, the Gulf Coast and New York, prices will jump even higher in coming weeks, said David Hackett, president of Stillwater Associates, which has produced a report critical of gasoline price caps.

"We know next week it will be higher," he said. "We're fairly confident that the following week it will be higher still."

If consumers react to that threat of higher prices by filling up tanks and hoarding gasoline, "stores will run out of gasoline this weekend," Hackett said. "They (consumers) shouldn't do that. The system isn't resilient enough to handle big demand swings.

"People are going to have to think about that and decide what they want to do."

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