Imagine discovering a friend or loved one misunderstood their car’s dashboard gas gauge arrow so badly, they run their tank bone dry. Every. Single. Time. You might laugh. You might even tease them. But mostly, you’d be wondering how haven’t they been stranded by the side of the road yet?

Redditor Jooosh8696 and his girlfriend disagreed on the purpose of the little arrow next to her gas gauge. He (rightfully) claimed the arrow pointed to the side of her vehicle with the gas filler cap. She believed that she should wait to refuel when her gas gauge needle was lined up with the arrow. Translation: plunged deep into “E” without a drop left in the tank. When he asked the internet to weigh in, Redditors explained just how dangerous this practice is for an engine.

Joosh8696 certainly picked the correct subreddit: StupidCarQuestions. He posted a picture of the dashboard with the gas filler cap directional arrow circled. He explained: “Girlfriend says you should fill up when you reach this symbol, I thought it just told you that that gauge indicates fuel, and which side the petrol cap is on.”

What’s the directional gas arrow for, anyway?

As I previously wrote, that little arrow next to your gas icon isn’t a countdown to doom. It’s an elegant lifesaver for the forgetful—pointing to the side of your car with the fuel door. It costs nothing for automakers to print and saves you the shame of doing gas station pirouettes in a rental.

The first gas arrow showed up after Ford designer Jim Moylan was testing a new model and got soaked switching pump sides in the rain in 1986. He went straight into the office and pitched the fix. By 1989, Ford Escorts had gas arrows. Mercedes had actually done it earlier in 1976 with a triangular fuel warning light, but they dropped the idea. Ford made it stick.

The danger of running your tank dry

Running on fumes isn’t just risky—it’s rough on your ride. Modern fuel systems rely on a small in-tank pump, which uses the fuel itself to cool and lubricate. Less fuel means more heat and wear. Over time, that abuse can fry your fuel pump or clog the filter with debris from the tank bottom .

As Redditor JustMyRealName put it: “When you run low on fuel it is working harder… on an older vehicle you may have some sediment… and a higher chance of it getting picked up in the pump.”

Another user, TheRealFailtester, shared their painful lesson: “Go figure, there was crap in my tank, picked it up, and plugged it solid… $45 bucks down the drain.”

Filling up at a quarter tank might not sound cool, but it beats praying your rust flakes don’t hit the injectors. TrollCannon377 said it best: “You really should fill up when you get to about 1/4 of a tank to avoid gumming up your fuel filter.”

And as for the girlfriend’s interpretation? Reddit was not gentle. “She’s not right, technically or otherwise,” said Nocryplz. Another user, Organic_JP, offered a blunt solution: “No it means it’s time to get a new girlfriend.”

So maybe she’s not the “gas arrow whisperer” she thinks she is. As Creepy_Statistician8 bluntly put it: “NO! If that has you confused please use UBER!”