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DENVER — Drivers in Colorado have been enjoying lower gas prices for months. But for some, a fuel discount is costing them a lot more than they could have imagined.

On June 1, the King Soopers at West Evans Avenue and South Clay Street sold customers the wrong fuel by mistake.

“I gas here all the time,” customer Sean Williams said.

He likes how close the fuel station is to his home — not to mention the discounts. But a mistake by a fuel supplier has him reconsidering filling up there again.

“Being that the wife drives the car you know, (her getting) stuck on the highway or something, in the hammer lane, especially. Yeah, that’s a no go,” he said.

A fuel supplier accidentally filled the underground unleaded gasoline storage tank with diesel fuel instead. King Soopers spokeswoman Kelli McGannon said 50 drivers unknowingly fueled up at 10 of the pumps. Twenty of them filed damage claims.

“I’m glad that wasn’t me that got that. I’d have to replace my motor probably,” said Mike McAninch, who filled up his work truck Wednesday.

Drivers said the fixes are costly. One mechanic said they average $3,000.

“I just hope these guys are paying more attention,” Williams said.

“I don’t know if somebody wasn’t on top of it or what. That’s a pretty risky mistake, costly you know,” McAninch said.

A costly mistake King Soopers said it fixed the next day. It had to pump out the wrong fuel and clean the tank. And now customers hope the grocer’s promises to pay for the problem don’t run on empty.

McGannon wouldn’t identify the supplier but did say the grocery chain is making all of its fuel station suppliers review their procedures when filling storage tanks so the mistake doesn’t happen again.

Anyone with concerns about gas quality can call the state’s Division of Oil and Public Safety at 303-866-4967.

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