How To Siphon Gas


While it is not something that one would usually advise people to do, knowing how to siphon gas can be very useful as a skill in case of an emergency.

Yes, learning how to siphon gas is not a crook’s job, but something that might come in handy in a variety of scenarios, such as running out of gas when you are miles away from civilization or a petrol station when you mow your lawn and can’t be bothered to visit the petrol station to fill up the lawnmower’s tank.

How To Siphon Gas

However, siphoning gas from newer automobile models is extremely difficult because of the newly installed anti-siphon mechanisms.

Even in this case, though, it is not impossible, and all you need is to get some specialized equipment, and have some technical knowledge and creativity!

How Can I Siphon Gas?

1. Unlock The Fuel Filler Door

You probably already know how to open the fuel filler door but, even if you don’t, it is a very simple step. Just add some force to open it and use a tool to do it.

2. With A Tool, Lift The Flap Over The Filling Pipe

Most gasoline pipelines are protected by a metallic flap that makes it possible for you to put a tube in. However, you might find it has to take out the tube after that, so you should get a long, slender instrument to get around this.

3. Drain The Gas

You can drain the gas by putting one end of the tube in the tank and having the other one lead the fluid in the canister.

However, do remember that, since siphons are going one way, you must make sure not to put it the other way around.

Then, all you need to do is to keep pressing the valve; you will see the gas moving from the tank into the canister.

Another piece of advice we can give you for this step is to try not to use your mouth to squeeze the gas as in the slight chance you swallow gas the consequences might be too severe.

You probably heard of many people doing this, but it is best to use a siphon with a bulb that can do the work for you.

What About The Anti-Siphon Valve? 

If you own a modern car, then it is most probable that it came with an anti-siphon system, that you must find a way to go around to pull the gas out.

What Is An Anti-Siphon System?

What Is An Anti-Siphon System

There are two gadgets available that can make it harder for you to siphon gas from your vehicle. Number one is a siphon-prevention screen and what it does is block solids and not allow them to enter the gas tank. The screen is usually near the top of the gasoline filler pipe.

Number two is a “rollover outlet”. This mechanism is installed at the tank’s inflow and is designed to restrict gas from fleeing the automobile in the case it actually rolls over in an accident, while, at the same time, it stops you from inserting a siphon tube into the tank.

Can I Go Around The Anti-Siphon Valve?

The short answer is yes. But you are probably wondering how you can do that, so here are a couple of recommended methods you can follow.

Method 1: Park On A Downhill Road

If you have a vehicle with a siphon-prevention screen but no rollover valve, you should be able to siphon an adequate amount of gas using this easy approach, as the screen is normally situated relatively way below the filler pipe’s neck.

So, you need to simply leave your vehicle on a downhill road or slope so that the filler will be facing downhill. Then, you can use your tube to take out some of the gas.

Method 2: Remove The Anti-Siphoning Screen

The second method is not one I will encourage you to follow, but, if necessary, you can break the siphon-prevention screen.

The reason why this is not an ideal solution is that there is a chance you will end up with parts of the screen clogging the fuel channel in case they accidentally get dropped in there.

However, if you choose to go down that road, you will need something that is pointy and is long enough to pierce the screen, as two metals contacting might cause a spark, which might, in turn, start a big fire.

Therefore, using something like copper is a great option as it is one of those materials that will most likely not spark.

So, what you can do is make a copper ring and fuse it together with a pipe made from the same material, and then feed it into the gas tank and break the screen with the ring.

Method 3: Disconnect The Fuel Line And Drain The Petrol

This is much easier to do, as you can just reach the gas from the opposite side of the tank instead of attempting to bypass the anti-siphon systems and mechanisms in place.

Method 4: Use A Gasoline Pressure Tester Equipped With A Bypass Valve

To go around the anti-siphon outlet, utilize the fuel tank Schrader valve which is used to measure the gas pressure. However, since not all vehicles have fuel line Schrader valves, this may not be your case.

If there is a Schrader outlet, a pressure test kit with a bypass outlet is required to connect it, place the outlet tube in the canister, and turn the bypass on to let the gas flow in the canister.

To make this happen, you have to turn the engine on. So, if you are not aware of how a vehicle can jumpstart, this method can only work for your car.

Method 5: Open A Hole In The Fuel Tank

The last option is to extract gas from a vehicle by opening a hole in the tank and letting the gas run in the canister that you will have placed right under the hole.

However, it is obvious that this method would lead to the gas tank being ruined in addition to the greater risk of catching fire as, as we said, the two metals contacting can lead to a fire situation.

Therefore, if you have to use this method, I suggest you do it only in the case that your gas tank is made of plastic material.

The Bottom Line

As you can tell, a number of these ways provided to siphon gas require you to run the car’s engine at the same time, a practice that poses quite a risk.

As a result, you should make sure to not only siphon gas from an engine that hasn’t been on for a long time but also to use a tube that is long enough to keep the canister at a good distance from the vehicle. 

So, if you want to siphon gas from your car, you should go with the safest of these options, be well-prepared, and know well how to do it.

Matthew Osborn

Matt is an entrepreneur who has created and successfully exited multiple companies and brands. Now, he dedicates his time to Legionary, where he produces content on guns, family, and freedom.

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