Why Does My Car Smell Like Gas?

Five things to look for when you detect gas fumes in a vehicle.

Benjamin Hunting | 

Sep 27, 2024 | 3 min read

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Slipping behind the wheel of a vehicle only to encounter the smell of gas is generally unsettling. A gasoline smell could indicate that you're dealing with a dangerous situation that may require the intervention of a professional mechanic in order to avoid injury.

Still, not every whiff of gasoline heralds imminent peril. There's more than one reason you might detect a gas odor.

Check Your Hands and Feet for Spilled Fuel

If you've just filled up your vehicle with fuel, you could simply be inhaling the results of a spill. An estimated 400 gallons of fuel are spilled at the average gas station during a 10-year period, according to a study published in the Journal of Contaminant Hydrology.

This means there's a strong chance you're stepping in a puddle either of your own making (due to drips from the nozzle) or left there by the person who used the pump before you. Tracking that fuel into your car's closed cabin will instantly fill your nostrils with fuel smell.

You may even have gotten a few drops of gas on your hands when removing or replacing the fuel cap or the filler nozzle. The gasoline can be absorbed into your skin and produce the same smell.

Make Sure Your Gas Cap Is Tight

Your car's fuel system operates under pressure, and if the cap is loose — or if you left it behind on top of the fuel pump — fumes from the tank can escape and enter the passenger compartment. This is especially likely if you have your windows down or you are stopped at a red light. Check to make sure that the cap is tight — and present — so you can rule this out.

It Could Be an Overactive Fuel System

Fuel injectors are designed to deliver just enough gas to each cylinder so that it can mix with air and be ignited by the spark plug to generate power. If too much gas is sprayed, it may not all burn, with the leftover fuel causing a stink. An injector that's spraying more gas than it's designed to can lead to a gas smell while the vehicle is running.

There May Be Evaporative-System Venting Issues

Since gasoline evaporates quickly into the atmosphere if it's not kept inside a sealed system, modern automobiles include something called an EVAP system (short for evaporative emission control) to prevent them from polluting the atmosphere. If this system isn't properly managing gas fumes, they could end up venting somewhere you can smell them. Fume or fuel leaks like this are generally best handled by a professional mechanic.

You Might Have an Actual Fuel Leak

Unlike most of the other issues on this list, a fuel leak poses an immediate danger. Gas dripping from a ruptured line, a hose whose clamp has fallen off or loosened, or even a perforated fuel tank present a fire risk in addition to an olfactory insult. If you can see fuel dripping or spraying beneath the car or in the engine bay, or collecting in a puddle, shut down the engine and call for a tow to your mechanic.

Benjamin Hunting

Benjamin Hunting is a writer and podcast host who contributes to a number of newspapers, automotive magazines, and online publications. More than a decade into his career, he enjoys keeping the shiny side up during track days and always has one too many classic vehicle projects partially disassembled in his garage at any given time. Remember, if it's not leaking, it's probably empty.