OKLAHOMA CITY - That 100% gas that you may use to fuel your car could be getting more expensive or even might become extinct at your favorite fuel-up spot.

For many drivers in Oklahoma it is non-negotiable when it comes to fueling up.

"I have to have non-ethanol gas, no way around it," said Kim Monse as she was filling up her car at Petro Plus near I-44 and Kelley.

"Gas with no ethanol," agreed Steven Liggens.

They both argue it's better for your engine and gas mileage. But Federal EPA requirements are forcing refineries to produce more fuel blended with ethanol. Which means there will be less pure gasoline produced making it harder for gas stations to find.

"Our mainstay is real gasoline, we hope we can keep the flow coming here," said the Petro Plus manager Rex Rogers.

Rogers says they have worked out a deal with a local refinery. But the lack of supply may push up the price.

"We don't want it to be but it may turn out that's the case," said Rogers.

Leaving customers with some tough choices.

"I'm still going to buy non-ethanol gas," said Monse.

"If it goes up anymore I'm going to be walking," laughed Liggens.

Other retailers say they are still looking at options on how to get that pure gasoline.

Those in favor the increasing the ethanol blend say ethanol has made gasoline cheaper for all of us, and extends the fuel supply. They also say there is no proof that Ethanol damages engines or decreases performance.