PINEVILLE, NC -- Filling up your tank can be costly.

But what if you weren't getting what you actually paid for? According to professional inspectors, these things happen more than you think.

Within just a matter of minutes, during the early part of the morning, Inspector George Grier found several pumps at this Circle K on Polk Street in Pineville out of compliance.

Inspectors say during 2016 statewide, they found 3,297 pumps out of calibration -- that's about four percent.

"If you look at the list right here it says out of calibration," Grier said. "What does that mean to the average driver who may have been at that pump this morning? What would've happened with their gas situation?"

"On this particular pump, they probably would have been shorted less than a gallon of gas," Grier added. "But they would have been shorted."

But in addition to being shorted fuel, skimmers are also a major issue and something state inspectors are on the lookout for.

The North Carolina Department of Agriculture between April of last year and June of this year, 25 skimmers were found at pumps across the Tar Heel State.

Many of those have been reported on NBC Charlotte. Skimmers steal your credit or debit card information and the crooks can easily drain all of your cash.

Meanwhile, drivers we spoke with say they say it's tough to know what you're getting in your tank and thankful inspectors are out here checking.

But don't think they are able to be everywhere all the time. We discovered most of these pumps are only checked only once every year.

"Just making sure everybody's getting their moneys worth, you know, and getting good quality gas and keeping a good check on that," said James Belcher, a driver.

And when inspectors find a problem out here they go ahead and tag the gas pump just like this and put the sticker on it. That keeps anyone from using this gas pump until the owners or managers of the stores can bring the pumps back into compliance so drivers to get what they pay for.