COLUMBIA — Wondering if you're getting your money's worth as you pump $4-per-gallon gas?

A team from the state Department of Agriculture worked Tuesday to reassure consumers they are not getting ripped off.

With complaints tripling in the last year and not likely to stop with rising prices, Carol Fulmer, director of consumer services for the department, broke down the steps the state's 20 gasoline inspectors take to check the quality of fuel and the accuracy of South Carolina's nearly 65,000 pumps.

Motorists want to know why the gas they pump is not giving them the road miles they expect, if they're being sold fuel that's been mixed with water and why prices differ between stations.

"It's ridiculous," said Buddy Neeley of Columbia, as he pumped $40 into his white Chevrolet Silverado, not even enough to fill the tank halfway.

A former Summerville resident, Neeley fell in love with Charleston's waterways, but bringing his boat out of storage won't be happening anytime soon if he has to keep paying about $300 a month just to drive, Neeley said.

Many consumers are paying close attention at the pumps to make sure they're getting the amount of fuel they are being charged for, Fulmer said.

Some folks measure the pump readings against mileage clocked on their odometers and the size of their tank. Fulmer said, though, the pumps are actually more accurate at measuring gasoline than a dashboard odometer or a vehicle's tank.

That's because of pump calibration standards and the fact that vehicle manufacturers' specifications are approximate, Fulmer said. Also, gas tanks tend to expand over time.

It is the same principle for measuring fuel pumped into 5-gallon gas cans, Fulmer said.

"They are not an accurate measure," he said.

Another common complaint, Fulmer said, is pumps that have prices that "jump" when activated. That's a problem with pressurization, he said. In those cases, it's best to ask the attendant to reset the pump.

Many motorists are worried that the gas they pump might be diluted with water but Fulmer said that's a myth: gasoline and water won't mix. Still, inspectors test the pumps to make sure no water or other contaminates are being dispensed.

"If they suspect water is in the fuel, they should call immediately, but they might not know until they go to the garage," Fulmer said.

As for the price, that's set by competition.

"It's our job to make sure you're getting your money's worth," Agriculture Commissioner Hugh Weathers said.

The agency tries to test each pump during an unannounced visit once a year and every time a complaint is made.

In the last year, the agency found that 1.7 percent of the state's pumps were in violation, the bulk of problems were with pumps that give either more fuel than consumers are charged for or less, Fulmer said. About 1.2 percent of pumps in violation dispense the wrong amount of fuel, about half of which gave too much, he said.

A recent Watchdog analysis by The Post and Courier found that of 225 pumps in the tri-county area, about 2.1 percent were giving out too much fuel or short-changing customers during the past two years.

Pumps that are off by 12 cubic inches or more are shut down immediately. If it is less, the station has 10 days to make repairs, although pumps are given leeway for up to 3.3 fluid ounces for every five gallons. At $4 per gallon, that's a leeway of about 10 cents of gas.