NEW YORK (Reuters) - Gasoline stations around Florida struggled to keep up with demand from customers anxious to fill tanks as Hurricane Irma approached, with some locations running out of supply on Wednesday. Some convenience stores are out of fuel as delivery trucks wait three to four hours to get cargoes from Port Everglades, the main supply source for the southern part of the state, said Ned Bowman, executive director at the Florida Petroleum Marketers and Convenience Store Association, which represents 98 percent of fuel sold in Florida. Deliveries in the southern part of the state have been slowed by heavy traffic as residents evacuate.  The Category 5 storm, with winds exceeding 185 mph (295 km/h), clobbered Caribbean islands on Wednesday as Florida officials called for evacuations ahead of expected landfall this weekend. It would be the second powerful storm to hit the U.S. mainland in as many weeks, following Tropical Storm Harvey.  Filling stations in Orlando struggled to keep up with demand as early as Tuesday, with some running out of fuel or facing long lag times for resupply. Deliveries are usually made on an as-needed basis within an hour of a station signaling low fuel levels.  We re normally not even super busy at our pumps, and there are people parked behind each other right now, waiting,  said Eli Brito, shift manager of a RaceTrac station in Orlando that was out of regular fuel on Wednesday after waiting four hours for delivery on Tuesday.  Gasoline prices in Florida hit $2.71 a gallon on Wednesday, up 42 cents from a month ago, according to motorist advocacy group AAA. Florida has no refineries and its more than 20 million residents rely on refined products delivered by tanker and barge at its ports. On Wednesday, the U.S. Environmental Protection Agency said it would allow diesel fuel normally restricted to off-road use like farm equipment to be sold for highway vehicles that use diesel through Sept. 22, due to the approaching storm. The U.S. Coast Guard limited movement of ships into and out of the ports, including Port Everglades, which houses about a dozen fuel terminals. Commercial traffic is still allowed, said Coast Guard Petty Officer Brandon Murray.  The Coast Guard plans to further restrict traffic at the port midday Thursday, and require ships to make final mooring plans by midday Friday. No timeline for port closure has been set. Port Everglades had supplies on hand through mid-September when Harvey hit Texas, spokeswoman Ellen Kennedy said. The port usually has about two weeks of fuel available, she added. The state s other fuel-receiving ports, including Jacksonville and Tampa, remained open, said Bowman.  We ve been down this horse race before,  Bowman said from Florida s emergency operations center ahead of the storm.  