What To Put in Gas Tank To Ruin Engine? Welcome to the Madness!

Whether you want to experiment or play a prank on someone you hate (we advise against it, though), you have to know for sure what to put in gas tank to ruin engineLet’s get familiar with some engine-wrecking ingredients and their effects!

What To Put In Gas Tank To Ruin Engine?

Have you ever wondered what could be the worst thing to put in a gas tank that will damage or stall the engine? If you are a car geek, these weird questions bug you sometimes.

The answer is – there are several ingredients that you can use to do that. Some will just stall the engine and others may damage or corrode its components. Here is how to ruin a car engine through the gas tank!

The sweet little sins!

If you are just mischievous and do not want to destroy the engine, use sugar or any other sweet, sticky liquid. 

what to put in gas tank to destroy engine
Sugar will stall the engine and gradually destroy it. (Photo: Gizmodo Australia)

Sugar in a gas tank is an urban legend and it will clog up the fuel filter, just like other sticky sweet liquids such as honey, molasses, waffle syrup, pancake syrup, and similar things. Because sugar does not get dissolved in gasoline.

So, even if some sugar gets sifted through the fuel filter and passed through the fuel line, it will sit at the bottom of the tank. These ingredients won’t do major damage to the engine but will stop it after a while. 

You have to clean or even worse, change the fuel filter, fuel pipe, and gas tank to remove their traces from the system.

Check out the video below from Project Farm to see more details on the effect of adding sugar to your gas tank and how long does it take sugar to destroy an engine. 

How to destroy an engine with bleach?

What to put in a gas tank to ruin the engine? Mixing gallons of bleach with the fuel is the perfect recipe for disaster! Never put it in your gas tank unless you are suicidal or want to destroy your car for some weird reasons. 

The vehicle will run at first but will halt altogether when there will be no trace of fuel in the tank. If you leave it too long inside the fuel system, it will corrode and cause rust to several engine components because it contains chlorine – a highly corrosive oxidizer.

Let’s watch what happens if you fill up a car with bleach, video from TechRax

How to destroy a car engine undetected? – Pour water!

Seems confusing? Why would something ‘normal’ like water disable a tank by damaging the engine? Take the cue – anything that is not fuel is harmful to an engine. You will be surprised to know that more than 90% of bleach is water, and it still is detrimental to the engine. 

So, mixing water into the fuel will create the same effect, except for the corroding and rusting part. If you are unaware and keep driving, the car will run like a wild horse and can actually detach the engine from the engine mount.

how to ruin a car engine
Pouring water is also harmful towards your engine. (Photo: Vehicle Wisdom)

FAQs on Worst Things To Put In Your Gas Tank

1. Is putting sugar in a gas tank a felony?

It is prohibited to put sugar in a gas tank. However, whether the offense is a felony or a misdemeanor is determined by a variety of factors.

2. What happens if you put salt in a gas tank?

If this happens, the gasoline will absorb the salt and start to get soaked. Then this weird mixture will corrode the metal cover of the gas tank, eventually causing it to leak or brake. In addition, through time, the salt will eventually get to the engine and potentially create a fire within.

3. Can you put vinegar in a gas tank?

Vinegar is an acid with a 5-15% concentration of water. It will not burn in the engine, so don’t expect it to start. Because it is an acid, it is corrosive. Leaving it in the petrol tank and running the engine will corrode the engine and everything it goes through.

However, vinegar is super helpful when it comes to cleaning and flushing the car gas tank in due course. The most secure way of chemical rust removal is to fill (or almost fill) the tank with vinegar and baking soda. 

For the steps, you can first allow the mixture to rest until it begins to bubble and change color with the rust particles. Then carefully rinse to ensure it’s entirely empty.

4. Will adding Coke in your gas tank cause any harm?

Coke in a gas tank is equivalent to ruining the engine’s internal structure. The sugar amount of Cola-cola is so high that it can damage the engine, only at a slower pace compared to a direct sugar.

Furthermore, the liquid’s viscosity and sticky nature would cause immediate and long-term damage to the engine.

how to ruin a car
Putting coke into the gas tank is one way to ruin your car quicker. (Photo: Carscoops)

5. What happens if you put soap in a fuel tank?

Apart from not being combustible and forcing the engine to stop, soap may inflict expensive damage. If soap ends up in a gas tank, it will most likely block the fuel system and cause the engine to fail very fast.

6. Can I mix alcohol with gasoline?

Gasohol is created by combining alcohol with gasoline. The benefits of gasoline mixes include increased octane rating and lower carbon monoxide (CO) and other exhaust emissions from the engine. 

A fuel’s octane rating reflects its resistance to knock (abnormal combustion in the cylinder). Most gasoline already contains some form of antifreeze for gas lines.

If you find it handy, you may add alcohol to your tank in the same proportion as a commercial dry gas product, around 12 ounces of isopropyl alcohol for every 10 gas gallons.

7. What is the best alcohol for fuel?

Each driver will have their own standard to rank an alcohol type that works best with fuel. People can recommend ethanol, but methanol may be a little bit more suitable for those who want powerful performance. 

Methyl alcohol has the least amount of combustion energy of any of the fuels mentioned. It does, however, have the lowest stoichiometric, or chemically accurate, air-fuel ratio. As a result, a methyl alcohol-burning engine would provide the strong power.

On the other hand, methanol, like other transportation fuels, is hazardous and should not be consumed too often. If the alcohol level of the gasoline used is too high, car engines might be ruined. 

To be sure, optimize it as a mixture. The methanol and gasoline mixture enhances the octane of gasoline and reduces engine knock caused by excessive heat or pressure.


Is there anything else to add to this list? Yes! You can also try hydrogen peroxide and the wrong fuel. Many people use peroxide as an additive, which is a big mistake because it is a reactive ingredient.

On the other hand, putting the wrong fuel might not do any major damage but your car won’t start at all and even if it starts, the performance will be poor.

We have just scrolled through our notices on what to put in gas tank to ruin engine. Hope you can be aware of the worst thing to put in gas tank and prevent any mistake that can completely destroy your engine without any warning.