The pumps don’t lie (but your gas tank might)
97.1 percent accuracy at dispensers in county

By DAVE RANK - Daily News

Nov. 20, 2014

Weights and Measures Petroleum Inspector Joel Kohlman tests the accuracy of a gas pump at the East Side Market BP gas station on Wednesday afternoon in Jackson. Pumps are inspected at least once a year to make sure the consumer is getting an accurate amount of gas for the money listed.
Photo by John Ehlke

When you drive up to a gas station to fill up your car, rest assured you have a better than 99 percent chance you will get your money’s worth or more in fuel from that pump.

“Gas pumps are among the most accurate devices out there,” said Jay Garbe, the Weights and Measures Petroleum System supervisor for southeastern Wisconsin, part of the state’s Department of Agriculture, Trade and Consumer Protection.

“We have very few problems with them. If anything, consumers are getting more than they pay for,” he added.

Statewide for 2013, the latest figures available from DATCP, 30,835 fuel grade dispensers were tested with a 97.4 percent accuracy found. The 2.6 percent of pumps that needed to be recalibrated included both undercharges and overcharges, the DATCP reported.

So the percentage of pumps where consumers are charged accurately or undercharged (labeled consumer confidence by the DATCP) was 99.5 percent In Washington County, those figures were 97.1 percent accuracy for the 1,172 dispensers tested, and 99.8 percent consumer confidence.

“I haven’t heard any issues with it,” West Bend City Clerk Amy Reuteman said, whose department handles commercial weights and measurement equipment licensing in the city. “I don’t remember one ever going beyond a warning.”

DATCP stated, on average, fuel pumps in Wisconsin delivered 1.43 tablespoons more fuel per gallon than charged.

Weights and Measures Petroleum Inspector Joel Kohlman lifts a gas pump from a measuring machine to check the accuracy of the pump at the East Side Market BP Gas Station
on Wednesday afternoon in Jackson.

Photo by John Ehlke

Still, fuel pump accuracy consistently rates among the top 10 consumer complaints received by DATCP each year. In 2013, fuel pump accuracy was seventh on that list with 284 written complaints received.

For comparison, last year telemarketing was No. 1 in the consumer outrage standings with 2,014 written complaints received by the state.

So why the distrust in fuel pumps?

Garbe is not sure. “I think it’s just the cost of gasoline and a perception,” he said.

The testing equipment his inspectors use is extremely precise, measuring flows by the cubic inch. “There are 231 cubic inches in a gallon,” Garbe said.

However, the automobile industry is not so precise labeling its fuel tanks, Garbe said. “A consumer may think his or her gas tank holds 15 gallons. But it’s an estimate. It may actually hold 15.5. The gas gauge in your car is not that accurate either.”

The result is, a consumer blames a gas pump for overcharging, when the fact may be the consumer just misunderstands how much fuel his vehicle holds, Garbe said.

“It’s pretty minimal,” Weights and Measurements Petroleum Inspector James Dagenhardt said of inaccurate fuel pumps. “It does happen, but it’s not often.”

Dagenhardt is the state’s inspector for Washington County, Menomonee Falls in Waukesha County, the eastern edge of Dodge County and the Campbellsport area of Fond du Lac County.

Fuel pumps are tested for accuracy annually, Dagenhardt said. “If we get a complaint, we test it again.”

If a pump is found to be undercharging, he said, the business owner is notified. However, if a pump is found to be overcharging, the business is warned and given seven days to have that pump corrected or shut down for good, Dagenhardt said.

Weights and Measurements tests all fuel grades from a dispenser. A pump may dispense three or more grades of fuel, so each grade is tested. And a pump often dispenses from two sides, so it may have six or more fuels tested, Dagenhardt said.

The 1,172 grades of fuel tested in Washington County is not a direct count of fuel pumps, but of the various fuels dispensed from pumps in the county.

Municipalities issue the licenses for weights and measures equipment, including fuel pumps, Reuteman said. A few communities in the state have their own inspectors, but most, including all in Washington County, contract with DATCP for testing services.

Fuel pumps are tested primarily in the snowless months, Dagenhardt said.

“We try to get around to do those in the spring, summer and fall,” he said.

Winter months are directed toward testing other commercial measuring gear, he said.

DATCP’s Weights and Measures program also monitors the accuracy of all scales, package weights and price scanners in the state.