Americans are growing frustrated with rising gas prices, with the nationwide average hitting a four-year high of $4.53 in May 2026. Thus, it’s not surprising to see people trying different ways to fill up their gas tanks for less money. However, one Dodge Hellcat owner may be paying the price after trying to save at the pump.

TikTok user Atoyye Automotive (@stratoyye) shared a clip of himself filling up at a Shell gas station with 87 octane instead of the recommended 91 octane, hoping to save some money. He noted that he feels like he is filling up his car every day, which makes sense given that fuel consumption is one of the major cons of V8 engines.

“I’m finna see if it actually does something to my car or mess it up,” he said. When he initially starts up the Hellcat, everything seems fine — not even a single warning light. However, he later opened up the hood to reveal a very loud knocking sound. Could this be related to the half a tank of 87-octane fuel he filled up with?

Some viewers were not convinced that filling up a Hellcat’s tank with 87 octane once would cause any problems. Others, however, were shocked that the car could even start. Was the engine knocking from using the wrong gas?

@srtatoyye

Putting 87 in my hellcat gone wrong😳💔 #srt #atoyye #hellcat #hemi #mopar

♬ Last Breath in Forest – Izmi Maruf

The numbers at the pump indicate the fuel’s octane rating, which measures its stability and how well it resists knocking during combustion. The Dodge Charger SRT’s manual states that 91 octane is necessary to meet the Hellcat’s fuel economy and performance.

While we can’t know for sure whether the engine knocking was a result of Atoyye’s fuel hack gone wrong, engine knocking can be a side effect of putting regular gas in a premium-gas car. The lower-octane fuel may ignite too early, causing the knocking sound. This can eventually lead to other problems, such as reduced power output and efficiency, and may even damage the engine.