The mistake is likely to cost the company tens of thousands in repair bills.
Spokeswoman Karen Allan told Calgary Metro that Co-op's fuel supplier mistakenly filled a regular gas storage tank with diesel on Boxing Day.
It wasn’t until 26 hours later that Co-op was made aware of the problem.
About 500 vehicles had fuelled up at the gas bar by then.
Allan says Co-op membership numbers were used to track down and notify 476 members about the fuel flap.
“We were initially contacted by a member who had had some issues with their vehicle and that caused us to go back and double check, and that’s when we discovered the error,” said Allan. “That’s when we began contacting all the members that had gassed up that day.”
Nearby dealerships were also given the heads up, she said.
Calgary Co-Op has also offered to cover the cost of rental vehicles.
“All the repairs, anything that happened as a direct result of having this fuel in their tank, is being taken care of,” Allan said.
Christine Mork was one of the drivers who hit the pumps and fuelled up her Mitsubishi Outlander on Dec. 27 before heading for a mall.
She said it wasn’t until she received a phone message from Co-op on Dec. 29 that she realized anything was wrong.
“It will be covered, but it’s still a bit of a hassle, definitely,” she said.
Michael Hoang, assistant service manager at Calgary Honda, said the business has had six or seven vehicles come in for repairs after filling up at the Co-op gas station.
“On an average repair for a diesel fillup … I would say it would be about $1,000,” he said.
“It depends on what happens to the vehicle. It could range up from $3,500 to $4,000 if it needs everything.”
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