Is is true that an empty tank of gas will explode faster than a full tank?

Question

If so, why?

Bekki B

It is not silly to ask precisely what you don't know...

Bolivar
What the heck are you suggesting? You are paranoid.

Thank you all for your anwers. For the record we were discussing at work if a bigger car (bigger engine) is more dangerous to have than a smaller engine (in case of fire) and he said the size of the engine is not relevant but if the car's tank it's full or empty

Bolivar
Sorry my comment was intended to BOB

Answer 1

I am assuming you mean that the empty gas of tank will have more gas vapor than the full tank (more liquid gas). Yes, gas vapor is what really explodes. Liquid gas doesn't really explode, but rather fizzle.

However, if the tank doesn't have any gas period (truly empty), then a full tank of gas will explode much more easily.

Answer 2

I think what you are referring to is...will a nearly empty tank of petrol (gasoline) explode when a full tank of that same gasoline will not?

The answer is...yes.

Liquid gasoline burns, but it does not explode. Vaporized gasoline, the fumes, explode if the particulates (mist or molecules) are sufficiently surrounded by oxygen. The fumes explode because nearlly all their molecules are exposed to the oxygen in the air, which makes oxydization (burning) easy and quick. We call a really rapid burn an explosion, which is really just rapid oxydization of the gasoline molecules that make up the fumes.

On the other hand, only the surface molecules of liquid gasoline are exposed to air and its oxygen. Thus, only the surface molecules can burn. Relatively few molecules, when compared to the fumes, get involved in combustion during any given period. So number of gasoline molecules combusting per unit time (i.e., the rate of combustion) is lower than for fumes. That is, it burns rather than explodes.

You might be interested to know that anything like molecules or even fine dust suspended in air is subject to exploding. This explosive capability is due to the oxygen surrounded particulates (molecules or dust) making it easy to burn rapidly.

For example, grain silos have been known to explode when the dust in them is set off by a spark. Yet, the grain itself, will just burn. Or, coal dust in mines can explode if there is a spark to set it off. And, again, coal normally just burns. My point is this, gasoline is not the only thing that will explode when suspended in air.

Oh, and by the way, because liquid gasoline does not explode, liquid gasoline in the tank has to be changed to vapor (fumes) before it gets to the cylinders in a car engine. Otherwise, there would be no explosion to push the cylinders; the engine would not run. Carburetors and fuel injectors are the things that convert liquid pertrol into vapor.

Answer 3

It depends on the form of ignition. Gasoline tanks in cars don't actually explode often, even in major accidents. They do spill gasoline all over but liquid gas doesn't ignite that easily, like say, from a lit cigarette. It takes a significant open flame for that.

But... in an small space gasoline vapor will ignite much more easily. So an "empty" tank that has just the right amount of gasoline vapor will indeed ignite with a minor ignition source, like a spark.

Answer 4

Yes - because the only thing contained in the tank is gas vapor which is highly susceptible to ignition by a host of causes.

Answer 5

No, silly! Because there's no gas in it to explode.

Now partly full (but mostly empty).... That might give you the ideal mixture of air and gasoline vapor for rapid combustion.

Answer 6

Gas fumes are by far more flammable than liquid gasoline.

Answer 7

one gallon of gas has the equal explosive power of one case of 80% dynamite ( suspended nitro) so rotate your sticks but not your gas. that keeps the nitro from consolidating in one end. DO NOT FOOL WITH ANY OF THIS KIND OF STUFF