Some of these problems could short change the customer, with errors such as the gas pump starting to charge you before you even begin fueling.
"There have been some that have been way off," said Shelia Field. She's the General Manger of Plains Pump Company. It's her company's job to make sure customers get what they pay for at the pump.
"At the price of gasoline prices these days, it's very important that you get what you're supposed to," said Field.
Field and her team go to gas stations to make sure each pump is accurate.
While they're looking out for the customer, it's also their job to look out for the gas stations, and make sure they're not being cheated either.
The meters are kept down below the pumps, in a place the public doesn't see. These pumps must be checked, by Texas law, once every four years by the Texas Department of Agriculture.
When a pump fails, they are shut down until they can be re-calibrated.
"They take a calibration can, they pump 5 gallons into the can, and they make sure it measures up," said Field. "We try to get them as close to zero as possible." When the pumps are at zero, that means neither the customer or the station is being cheated.
One man we spoke to at local gas station said "It's hard to tell, they say it's accurate, so it's hard to just know."
So are you getting what you paid for at pumps around Lubbock?
We looked at records from the Texas Department of Agriculture back to September 2009.
Out of 149 businesses in Lubbock County, we found only 57 had a routine check done in 2012.
Meaning about 60% had not been checked this year.
"If it's in the favor of the service station, then the customers are getting shorted, and Texas Department of Agriculture checks them periodically, and if they're short, they will shut the store down because the customers are getting shorted," said Field.
A variety of reasons can shut down a store:
Short measure in excess of tolerance, improperly maintained, does not hold zero, and two times the tolerance.
All meaning the customer isn't getting what they're paying for.
"I think there's more complaints about it," said Field about when customers feel they are being cheated. "Not usually when people get too much, they don't complain."
Here are the two worst offenders we found: Stripes at 2025 Clovis Road and Stripes at 5801 19th Street.
In 2009, the state found both had 60 to 80% of the tanks in favor of the station, cheating the customer. Both then passed follow up inspections.
"For the customer, 60 to 80 percent, that's more than half the store," said Field. "I mean the device owner probably wasn't aware of this, I'm sure, but it's in their favor, so it's really not good for the customer."
We reached out to Stripes about their stores in Lubbock, and they sent a statement, saying "Stripes conducts our own, voluntary calibrations of all devices and meters at least once annually."
Field gave some advice for what to look at when you go to fill up at the pump.
Check to make sure everything starts at zero.
Take a look at the nozzle and make sure it's not leaking.
Know how much your tank holds, and make sure you're getting the right amount.
Do some quick calculations,know what you should be paying.
Field says that if you do think something is off, every gas pump has a sticker with the number for complaints (1-800-835-5832), or you can visit this website. Be sure to call that in, and within 10 days the pump has to be checked.
If you want to see pumps and their inspections by county, use this website.