5 Reasons to Never Top Off Your Gas Tank
There are a ton of urban legends about cars you’ve heard over the years since you got behind the wheel, from the uncle who taught you how to drive stick to that highway mechanic who fixed your flat on a road trip or the regular car guy talk at an auto meet.
Honestly, most of these stories are a bunch of baloney. You don’t need to warm up your vehicle every morning unless it’s from 70 years ago. Also, check your vehicle’s owner’s manual for maintenance advice, such as tire pressure or the type of gas to use—anything else is just wasting your money.
But not all these car talk stories are hogwash. For instance, do you top off your vehicle’s gas after the pump turns off? We’ve all witnessed or been victims of this petty crime—the pump shutting off just a few cents from a dollar.
Let’s be honest—only the most disciplined humans can resist squeezing in a few more drops to round off the charge.
Why It’s Important Not to Top Off Your Car’s Gas Tank
Filling up your car can be annoying, especially if you are in a rush and have to shave off some time to wait in line for a free pump. For these reasons, most drivers would rather get the best out of their time at a gas station – by lifting the pump nozzle and topping off their gas tank after the pump shuts off.
Well, according to industry experts, topping off your gas task could be doing more harm than good to your vehicle. It’s bad for the environment, damaging your car, and a safety hazard.
It Is Bad for the Environment
We are living in a time of environmental reforms, trying as much as possible to keep the earth healthy for our own good and future generations. Something that has seen the auto industry slowly start shifting from ICE (Internal Combustion Engines) to EVs (Electric Vehicles).
Topping off your gas tank often leads to spillage. Here’s the truth. Gas is a petroleum product derived from crude oil. It is a flammable, harmful liquid that, when spilled on the ground, can pollute soil, groundwater, and surface water.
When gas mixes with roof or stormwater runoff, it finds its way to local ponds, rivers, and lakes, where it can irreversibly harm plants and aquatic life over time.
According to the EPA (Environmental Protection Agency), oil from a single oil change pollutes about a million gallons of fresh water. Habitual gas spillage from top-offs only makes it worse.
It Is a Safety Hazard
You’ve probably watched gas station CCTV footage where fire sparks from something as simple as a cigarette lighter or a vehicle backing up into a gas pump, leading to an inferno.
That doesn’t happen every day, and it probably won’t happen to you or anyone you know. But in the event it happens – you don’t want to be the guy soaking their feet with spillage gas just because they wanted to round off the charge.
It Will Damage Your Vehicle
Topping off your car could lead to unwanted damage to your vehicle’s fuel system components. Vehicles manufactured after 1996 came with an ORVR (Onboard Refueling Vapor Recovery) system.
This device comes with a charcoal canister that collects harmful vapor from fuel while the pump nozzle fills your car. Activated carbon in the canister cuts down hydrocarbon emissions by more than 90%.
When you top off your gas tank after the pump shuts off, you add more fuel to the system, saturating the ORVR’s charcoal canister (with gas instead of vapor). Depending on your vehicle, the check engine light will pop up, at which point you’ll need to visit a service center to determine if your ORVR device is damaged.
The ORVR ideally lasts the lifespan of a vehicle, but topping off your gas tank will damage it over time, leading to hundreds of dollars in replacement and labor.
Decreased Performance
There’s a thin line between topping off and overfilling your gas tank. While topping off normally happens to round off the charge, the amount added can be equal to overfilling your tank.
When your vehicle’s fuel level is over the limit, it affects the fuel injection system, affecting acceleration. This might also lead to inefficiency and, as a result, poor fuel economy—which beats the logic behind topping off.
If you really want to save on fuel, try traveling light, coast more, and avoid idling over an extended period of time.