A car needs an engine to run, but an engine needs fuel to get running. Usually cars use gasoline or engine as fuel. However, other types of fuel also exist like biodiesel, bioethanol, LPG autogas and compressed natural gas. Hydrogen and electricity are now also used as fuels for cars.
There are times, however, that you might need to siphon the fuel from the tank due to some reasons. For instance, you might need to siphon off fuel from your car’s tank to be transferred into another vehicle. You might also need siphon off fuel from the gas tank of another vehicle to be transferred to your car.
Likewise, you might want to siphon off the fuel from the tank as you store away your car as it won't be driven for a long time. This is usually done due to safety reasons. In addition, you might want to siphon the fuel from your gas tank until it dries due to possible contamination.
There is one very common method of siphoning fuel from a tank. This is done by placing one end of a hose in the tank and the other end in your mouth. The suck the fuel, and before it reaches your mouth, transfer this end to the container where it would be transferred. Just make sure that the container is located lower than the tank to let gravity do the work. However, this method is very dangerous and could lead to a very unpleasant experience. You might swallow the fuel, inhale the gasoline fumes or lose consciousness in the process.
Nonetheless, there are better ways to siphon fuel from a tank. Two of them will be discussed here.
The first siphoning method employs two tubes, one of which is longer than the other. Insert one end of the longer tube into the tank, and the other into the fuel container. Then, insert one end of the shorter tube into the tank. Next, seal the fuel filler neck with a rag or any other soft material to keep the pressure – as created by blowing air into the tank -- from escaping around the tubes.
Now, blow air – either by mouth or a low-pressure air pump – into the short hose. If you are blowing air from your mouth, make sure that you won't inhale from the tube. The low pressure will force the fuel into shorter tube and into the fuel container. Don’t use a high-pressure pump as it may cause the fuel to come out from the longer hose in larger amount, possibly cause leaks or tank damage.
Once the fuel starts flowing, there is no need for further blowing as you can let the gravity do the job. After finishing the process, remove the two tubes from the tank and put the fuel cap back on.
The second method, meanwhile, uses a siphon pump. You can buy a siphon pump and always keep it inside your car for use in case of emergency. A siphon pump has two hoses, one of which will be inserted into the fuel tank while the other will be connected into a tank container. Before proceeding, read first which of the hoses will be connected to the tank or container. In between the hose is something like a rubber bulb, squeezable plastic or bike pump.
Now, connect the tubes to where they should be connected. Then squeeze the bulb, plastic or pump to commence the siphoning process. Once the fuel starts flowing, you can stop the squeezing action. After getting the right amount of fuel, take the hose out of the tank and put the fuel cap on.