What started as a simple act of kindness turned into a viral automotive mishap, sparking debate, laughter, and a hefty repair bill. On December 18, 2025, a woman in the United States set out to do her husband a favor by filling up his Ram pickup truck. But in a twist worthy of a sitcom, she accidentally pumped diesel fuel into the gasoline-powered vehicle—a mistake more common than most drivers realize, according to Motor1.
The error wasn’t discovered until after the truck had been driven four or five miles, at which point the engine sputtered and stalled, refusing to start again. “My wife said she put approximately a quarter tank of diesel in, and she drove it four or five miles, then it stalled out,” mechanic Mike Pfeffer recalled in his now-viral TikTok video. The couple’s troubles, however, were just beginning.
After the breakdown, the truck’s owner turned to a dealership for help. The quote for repairs? An eye-watering $4,000. The dealership’s solution included replacing the fuel pump, injectors, and a full flush of the fuel system. For most, that’s a bill steep enough to make you question whether the truck’s days on the road are over. As Motor1 explained, “The dealership quoted them $4,000. Then they went to Pfeffer, who’s a mechanic, for a second opinion.”
Enter Mike Pfeffer, known online as @autotechmike, who became an accidental celebrity in the world of automotive blunders. Pfeffer’s TikTok video chronicling the incident quickly racked up more than 174,700 views by December 19, 2025, drawing the attention of gearheads and casual drivers alike. As he approached the truck on a snowy day, Pfeffer explained, “I know he’s got the anti-roll-over valve. He can’t just stitch something down and siphon it out. So, we’ll have to drop the tank.”
But Pfeffer wasn’t ready to accept the dealership’s pricey prescription without a fight. “We’re going to try other things first,” he said in his video, suggesting that a less invasive—and less expensive—approach might do the trick. His plan: drain the contaminated fuel, clean the system, and refill with the correct gasoline, hoping to avoid major component replacements. “If we gotta do what the dealer quoted them exactly, we come in $1,200 cheaper than them,” Pfeffer added, offering the couple a glimmer of hope and a possible reprieve for their bank account.
One detail that caught Pfeffer’s attention was the truck’s fuel door design. Unlike most modern gasoline vehicles, which are engineered to prevent diesel nozzles from fitting, this Ram’s fuel cap featured a deep opening. “That’s exactly how she was able to get diesel into it,” Pfeffer observed, calling it a “design flaw.” He noted the absence of any label stating “unleaded fuel only” on the dash or inside the fuel door, which could have served as a last-minute warning. “The nozzle hole is way down there. I mean, way down there,” he remarked, highlighting how the oversight made the error easier to commit.
As the story gained traction online, viewers chimed in with their own advice and opinions. Some suggested bypassing the need to drop the tank altogether. One commenter wrote, “Forget dropping the tank, pull the line at the rail and toss in a test relay and power the pump, pump into a bucket and be done.” Another advised, “Unhook the return hose and power the pump to push the diesel fuel out. Don’t need to drop the tank.” Yet another added, “Disconnect the supply line and jump the fuel pump relay and pump it out.” Pfeffer, however, remained firm: “I swear no one listens to video or what I’m saying. I said we’re going to try other things and cheaper options first.”
While the internet’s collective wisdom can sometimes be hit or miss, experts agree on one crucial point: if you realize you’ve put diesel in a gasoline vehicle, don’t start the engine. According to Urbs Garage, “Putting diesel in a gas engine, even in small amounts, can lead to immediate problems.” J.D. Power and Capital One both stress that the best course of action is to have the vehicle towed to a repair shop, where professionals can drain the tank, flush the system, replace the fuel filter, and refill with the correct fuel. Starting the engine, even briefly, can result in rough idling, decreased power, knocking sounds, clogged injectors, and fuel pump issues. In worst-case scenarios, it can cause catastrophic engine failure, corrosion, and damage to the catalytic converter.
For the couple at the center of this saga, the ordeal became a teachable moment—and a source of unexpected internet fame. The TikTok video not only documented the repair process but also highlighted the importance of clear labeling and thoughtful engineering. As Pfeffer noted, “I do not see anything on the dash that says unleaded fuel only... when we open up the fuel door, I don’t see anything that says unleaded fuel only.” It’s a small oversight, but one that had big consequences.
The incident also served as a reminder of how easy it is to make mistakes at the pump, especially with so many different fuel types and nozzle shapes in circulation. According to Motor1, “Getting diesel and regular gas mixed up when fueling is more common than you might expect.” The basic rule, echoed by experts and commenters alike, is simple: if you catch the error before starting the engine, don’t drive off—seek help immediately.
As for the Ram truck, its fate hung in the balance as Pfeffer set to work. Would a careful draining and cleaning be enough to revive the engine, or would more expensive repairs prove unavoidable? Only time—and perhaps a follow-up TikTok—would tell. In the meantime, the story stands as both a cautionary tale and a testament to the power of second opinions, internet crowdsourcing, and a little mechanical know-how.
For now, the diesel-filled Ram has become a legend in its own right, sparking conversations around BBQ pits and garage workbenches across the country. And as drivers everywhere double-check the pump handle before fueling up, one thing’s certain: sometimes, a good deed can lead to a great story.
