A petrol station in Selwyn has potentially forced a dozen of its customers to fork out hundreds of dollars in repairs after a fuel mix-up at the pump.

Customers have complained on a Rolleston social media page that they’d gone to fill their car at a local Allied Petrol station with Unleaded 95 but got diesel instead.

The issue reached the ears of Fuel Rescue owner, Nick Collet, who specialises in fixing fuel issues in cars.

Collet told NZME he’d received at least 10 calls on Friday morning of the issue, he had another 10 people to call back.

 “In the past, [the mix-up] will normally be a tanker putting the wrong thing in the tank, mismatching the labels or putting the fuel in the wrong hole,” he said.

When the wrong medium of fuel is put in a car, drivers will normally first see the car being to lose power and possibly smoke up until they reach their location.

However, it’s when the engine cools, typically overnight at home, and commuters try to start their cars in the morning that they notice something’s wrong.

“It can be fixed, normally it fouls up the spark plug with the mix of diesel and oil, it stops the spark and stops the car from running,” said Collet.

To get the issue repaired depends on the vehicle, Collett reckons it can cost the average car owner between $300 and $1000 to get their car fixed.

Fuel stations will typically cover the expense, Collet said, with stations having their own insurance systems in place.

“It can be a dragged-out process sometimes,” he said.

“It’s a total inconvenience. Most people need their cars every day, every minute so they could be put out quite badly. "

Allied Petrol was approached for comment on the story.