John Kearns refuses to feel guilty whenever he drives his 2002 Volkswagen bug past his old reliable neighborhood gas station in search of cheaper prices.

"I'm disloyal," Kearns said flatly yesterday. "It used to be easy because it was near home. Now I'm an opportunistic gas purchaser."

Kearns, a Hawai'i Pacific University administrator from Manoa, has joined the untold throng of drivers who have altered their buying habits in the three weeks since the price of a gallon of gas on O'ahu shot up past $3.

They've broken old routines of shopping at the most convenient station or filling up whenever they were running low. Now, people like Michael Naylor of Hau'ula will pull over his 2000 Toyota Corolla whenever he sees a station boasting lowest prices.

"I used to buy gas in Ka'a'awa, but it's $3.45 now," said Naylor, an arts administrator for the state. "Now I'll drive all the way to Kane'ohe to buy cheaper gas."

Bob Swartz, who owns three Chevron stations — in Kalihi, Kane'ohe and Kailua — has seen the difference whenever Hawai'i's gas cap, the only one in the nation, pushes his prices up or down.

This week, with Swartz's prices set at $3.17 a gallon, business was clearly up. "We've had some pretty good days this week," Swartz said. "When the price is $3.17 at one corner and $3.42 at another corner, (customers) are going to drive around a little bit, there's no question about it. But I'm not sure it's a good idea, when you consider the cost of gasoline and how much it costs to find a way to save 2 cents. You probably spend a little more just looking."

Chevron's 60 dealers around the state have also struggled with distribution issues since drivers began filling up or stretching what's left in their gas tanks depending on whether prices are up or down, said Chevron Corp. spokesman Albert Chee.

"We are experiencing the consumer shift in our buying patterns because our deliveries are getting very challenging," Chee said. "People are buying a lot in some weeks and some weeks they're not."

For retailers, Swartz said, "it plays havoc with distribution."

The wide price variation from station to station is caused, in part, by the swings in wholesale prices under the gas cap, station owners have said.

The gas cap, which took effect Sept. 1, has led to more volatile wholesale prices. The cap is based on Mainland prices and a new cap is set each Monday. As Mainland prices have risen rapidly in the wake of Hurricane Katrina, the wholesale price here has varied by as much as 50 cents from Sunday to Monday.

Two neighboring gas stations may have big price differences because they bought their wholesale gas at different prices. The dealer who bought at a higher price may keep his retail price high until he gets another shipment. Meanwhile, his competitor across the street may get a shipment of cheaper gas and immediately lower her prices.

The variations in price haven't turned all drivers into bargain hunters. Many said they're still hanging on to their old buying habits — no matter what their usual station happens to be charging.

"I'm lazy," said James Kuroda, a Nu'uanu artist.

He continues to pull his 2000 Toyota Corolla up to the pumps in Pauoa even though he knows he could probably find a better price somewhere. "I do it just out of convenience," Kuroda said.

His friend Lisa Yoshihara used to spend $36 to fill up her six-cylinder, 2000 Toyota Camry. Now it costs her $37 for just half a tank. But the extra cost isn't worth the hassle of shopping around for Yoshihara.

"I go wherever it's convenient," she said. "Time is money."

Russell Ishida, a Kaimuki trumpet player with the Royal Hawaiian Band, might have a better excuse than most for not paying better attention to prices.

In March, he bought a 2005 Toyota Prius hybrid gas-electric car that gets 48 to 51 miles per gallon. But Ishida's reasons for sometimes paying higher prices have little to do with the cost.

"I've always just stuck with Shell" gas, he said. "It's easy because I just use my Shell card, that's why."

But Jeff Philpott may have found the best reason of all for pulling over his 2005 Toyota Corolla whenever — and wherever — he feels like it.

With gas prices jumping in the last few weeks, Philpott finds it easier to simply ignore the cost and fill up on his own schedule.

"That way," Philpott said, "It's less painful to think about."

Reach Dan Nakaso at dnakaso@honoluluadvertiser.com.