Dozens of cars reportedly broke down this past week after filling up at a pair of Colorado gas stations, where for some unknown reason the cars were filled up with the wrong kind of fuel.

According to Fox 31 Denver, these breakdowns occurred to customers who filled at either a Circle K in Boulder or a King Soopers (a Kroger-owned regional supermarket chain) in Brighton. Both stations' gas pumps were delivering either gasoline contaminated with a significant quantity of diesel or diesel outright. The Circle K reportedly blamed "bad gas" with diesel in it for the issue, whereas the King Soopers attributed an outside vendor for its diesel-filled gas tanks.

"I got gas and about three blocks later, my car started lugging and chugging," said Dani Alexander, who fueled her 2015 Subaru Forester at the Boulder Circle K last Wednesday. "It's a really good car and I just got it tuned up on Friday."

Alexander called for a tow truck, whose driver told Alexander she was the second person they had towed with that problem that afternoon. Seeking compensation, Alexander called the Circle K that had given her the bad gas, and the station forwarded her to Travelers Insurance, which has agreed to cover the cost of her $1,100 repair, the tow, and refund the tank of gas.

"They did admit it was their mistake. That they had been delivered bad gas that had diesel in it, and that's where the plumes of black smoke were coming from," Alexander told Fox 31.

Vehicles that run on diesel are unable to run on gasoline and vice versa due to different combustion processes. Diesel engines utilize high compression ratios to squeeze air-fuel mixtures until they combust on their own, whereas gasoline engines operate at lower compression ratios and require spark plugs to ignite each cylinder. Fixing fuel mix-ups such as this usually requires draining the gas tank, fuel lines, and injectors. In some cases, fuel pumps may also need replacement.

Fortunately, gas engines will simply stop running when diesel makes its way into their cylinders, but had things been the other way around and gas was dispensed for diesel customers, the scrap value of the blown engines could've been enough to buy you a new diesel pickup.

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