The Murphy USA station next to the Walmart Supercenter at 3400 Singing Hills Blvd. recently became the first metro area retailer to sell E15, a blend of 15 percent ethanol and 85 percent regular gas.

Advocates for corn-based ethanol have pushed to broaden the availability of E15, which the U.S. Environmental Protection Agency has approved for use in all cars, trucks, vans and SUVs built since 2001. That accounts for more than 85 percent of U.S. vehicles currently on the road.

In Iowa, 31 stations now offer E15, said Lucy Norton, managing director for the Iowa Renewable Fuels Association. Most have been in rural communities, such as stations owned by farmers cooperatives.

Murphy expanded E15’s reach to more urban areas this summer and fall with the conversion of pumps in Sioux City and six other cities — Clinton, Davenport, Fort Dodge, Indianola, Mason City and Newton.

The only other Murphy station currently selling E15 is in El Dorado, Ark., the headquarters for the chain of 1,257 stations in 23 Midwest and southern states, most adjacent to Walmart stores.

Consumer demand drove the company’s E15 rollout in Iowa, Murphy spokeswoman Jennifer Forbess said.

“We felt that E15 would be accepted and appreciated in Iowa,” Forbess said.

Iowa, the nation’s largest corn producing state, is home to 43 ethanol plants, with the largest cluster in the northwest corner of counties.

Forbess said initial E15 sales at the Singing Hills Boulevard station have been low, but the company expects the volume to grow as motorists become more familiar with the ethanol blend.

“Our current challenge is to educate the consumers about what E15 is and what vehicles can use it” she said.

The blue-and white E15 pump caught Crystal Lammers’ attention when she stopped to buy fuel at the Singing Hills Murphy store earlier this month. So did the lower price, compared to the standard 10 percent ethanol blend, or E10, commonly known as Super Unleaded.

The Granville, Iowa, woman, though, opted to fill up with E10 as usual.

“I said, I better stick with what I know,” Lammers said.

The Murphy station now offers three different ethanol blends — E10, E15 and E85. E85 is as much as 85 percent ethanol. Unlike E15, the EPA has approved E85 only for vehicles with flexible-fuel engines.

A growing number of retailers in Siouxland offer E85, but just six — in the Northwest Iowa towns of Mapleton, Manning, Rock Rapids, Sioux City, Spencer and Storm Lake — also sell E15.

Norton said she expects the list to continue to expand.

“People are gravitating toward that fuel because of the economic value, and also because it’s a cleaner fuel and it helps the economy,” she said.

At the Murphy USA station Thursday, E15 was $2.03 per gallon, 10 cents less than Super Unleaded E10.

The 89 octane, E15 also is a higher performance fuel, compared to the 87-octane in most of the 10-percent ethanol blended gas, said Greg Popke, who operates a service station in Rock Rapids.

“It costs less money and you get better mileage. That’s the best thing about it,” Popke said.

Popke, the first Iowa retailer to start selling E15, said the blend now accounts for about 25 percent of his gas sales.

E15 would be an even better seller if not for an EPA rule that requires different labeling of the fuel in the summer months, he said.

From June 1 to Sept. 15, in most regions of the U.S., the EPA regulates the vapor pressure of gasoline sold at gas stations in an effort to reduce evaporative emissions from gas during the summer ozone season.

A waiver from the federal agency allows E10 to be sold in Iowa as a registered fuel in the summer. But the waiver does not extend to E15.

That requires Popkes and other station owners to switch the stickers on the E15 pumps in the summer, warning motorists to use the blend only in flex-fuel vehicles.

Popkes said the switch back and forth confuses many motorists.

“It’s a detriment to retailers,” Norton added of the rule. “It’s a major barrier to getting E15 into the market place.”

The only way to change the situation, she said, would be for a refiner to start shipping the low-vapor gas into the state.

In recent years, state leaders have done yeoman’s work to promote the sale and use of E15. In 2011, Iowa became the first state to incentivize the fuel, approving a 3-cents-per-gallon tax credit for every gallon sold. In addition, the state offers grants to offset the cost of installing new pumps or other equipment.

Despite the incentives, it’s unclear if more E15 pumps will be showing up in Sioux City any time soon.

Forbess said Murphy USA has no plans to add E15 at its other Sioux City station, next to the Walmart Supercenter at 3101 Floyd Blvd.

The Singing Hills location was an easier transition, she said, because it has four underground tanks, one each for E85, 87-octane, 93-octane, and biodiesel. A blending dispenser allows the station to mix E10 with E85 to make E15, she said.

The Floyd store, in comparison, does not have an E85 tank and it would be costly to now install one, she said.