Experiment shows how much gasoline evaporates from the fuel tank if parked in the sun

Gasoline is an extremely volatile fuel. It evaporates quickly, but have you ever wondered if the fuel in your tank evaporates when you park it in the sun? Well, here is an experiment that shows if fuel can leak out of the fuel tank.

Mechanical Tech Hindi’s video shows the experience. In the video, they fill a measuring cup with gasoline. According to the marking, there is about 910 ml of gasoline in the cup. With an ambient temperature of 33 degrees Celsius, the vlogger starts his stopwatch. After waiting two hours, the conclusion is that the fuel evaporation rate was much higher in the first hour compared to the second hour.

The timelapse video shows how the fuel level decreases over time. After holding the cup open for two hours, we can see that there is about 560ml of fuel left. Well, any type of volatile liquid evaporates if left open. The vlogger does not show the amount of fuel that would have evaporated from a fuel tank.

An experiment that uses a closed cup would have recreated the scenario much better instead of using an open cup. Vehicle fuel tanks are completely sealed and vapors do not escape from the tank.

Fuel tanks had vents

Decades ago, fuel tanks had vents to ensure that vapors didn’t build up inside the tank. This caused partial evaporation of the fuel. As manufacturers began to use advanced technology and modern engineers, manufacturers began to install evaporative or evaporative emissions recovery systems for short.

With the modern system in place, the vapors that form inside the fuel tank are passed through a charcoal canister. Charcoal absorbs hydrocarbons or many other systems have an overflow line that safely disposes of fuel to the ground.

On older fuel systems, the engine would draw in these vapors with a vacuum. But modern engines use engine control modules which usually control a small electric solenoid which opens and allows the engine to draw these fumes into the engine and burn them off.

So if you park your vehicle in the sun for long periods of time, don’t worry about wasting fuel. There will be a negligible amount that evaporates, if at all.

However, you should not park your vehicle for too long with fuel in it. If you plan to park your petrol vehicle for a few months, be aware that petrol has a shelf life. After contact of gasoline with air, the shelf life is about 6 months. There are additives available in the market, which can increase the shelf life of fuel inside a tank.