We learned recently on The Q Morning Show that Lou may not be entirely sure how to pump gas into her car and in that conversation Lori explained how to top off the tank. Well here are three reasons you should NEVER top off your tank after the pump clicks off.

Whether you're topping off because you want to round up the price to an even number or you just want to get as much gas into the tank as you possibly can, here are three reasons why experts say you'd should stop.

1. You Could Damage Your Car

Cars have vapor collection systems, basically a filter prevents harmful vapors from getting into the air. When you top off your tank, gas could get into that filter which in turn can cause your car to run poorly or worse, damage the engine. If you have to replace that system, expect to pay upwards of $1000.

2. You're Paying For Gas You Aren't Getting

Gas pumps also have a vapor collection system which feeds vapors and gasoline from the pump back into the gas stations tank. Any gas that it feed back because you put too much into your tank, you paid for, but didn't get into your tank. Sure it's not much, but then again, neither is the extra gas that actually does get into your car when you top it off.

3. It's Harmful To The Environment

When you top off, you run the risk of spilling gas. That's a hazard all around for you and the environment.