Regular gasoline prices could rise about 11 cents a gallon next week in Honolulu under the state's wholesale price cap law.

Coupled with a 14 cents-a-gallon rise this week, next week's forecasted hike would mean a 25 cents-a-gallon increase in the price cap during a two-week period. The estimated rise follows a jump in Mainland prices that serve as the basis for Hawai'i's maximum wholesale price for gasoline.

According to Democrats' calculations released yesterday, the increase next week will be 11 cents a gallon.

State officials today will announce the new wholesale gasoline price cap to take effect Monday. Advertiser calculations point to a rise of about 11 cents in the cap to $2.08 a gallon for regular on O'ahu. When taxes and a dealer markup of 20 cents are added, that could translate into pump prices of about $2.90 a gallon.

That would be the highest price ceiling for gasoline in Honolulu since the week of Oct. 24.

"Legislators have been monitoring the rise and fall of gas prices under the Fair Gas Price Law over the past four months, and it is now time to determine what actions we may take when the legislature begins next week," said Rep. Marcus Oshiro, (D-39th Wahiawa), the House majority leader. "The law is certainly working the way it was intended, and the dire predictions of disasters and shortages never materialized. However, we also need to gauge how Hawai'i consumers have been affected, and that will be an important factor in how we address the issue."

According to the AAA Daily Fuel Gauge Report, one year ago, the gap between Hawai'i gas prices at $2.42 and the national average at $1.77 was a difference of 65 cents. Today, the Hawai'i average is $2.69 and the national average is $2.32, a difference of 37 cents.

The cap sets an upward limit on what wholesalers can charge for gasoline. Wholesalers are free to price below the cap, but most have opted to set their prices near the cap to offset times when the law forces them to lower their prices, industry analysts say. Retailers have no limit on what they can charge at the pump.

Since the cap took effect on Sept. 1, local prices have tracked more closely with Mainland prices. At the same time, Hawai'i gasoline prices have been increasingly volatile.

The cap, set by the Public Utilities Commission, is based on the five-day averages of wholesale regular unleaded gas for the three spot markets — New York Harbor, Gulf Coast, and Los Angeles.

Reach Sean Hao at shao@honoluluadvertiser.com.