Device to Save Fuel

If I have an electromagnetic device connected to an internal combustion engine, such that the fuel particles passing through the device are "sorted", allowing the fuel to burn better and thus generating fuel economy.


This is the typical device that is offered on thousands of websites, but the truth is that this device does not work, but:


* what is the reason it does not work?


*i.e.* if the device is able to rearrange the particles should be affected the entropy, but I do not think that the device change the temperature of the system ... If someone can help me and tell me why this device does not work, I would be very grateful


Pd: Maybe is enough, compared to the efficiency of the engine with and without the device, but How I should compared this? .. .Thanks 




I'll set aside for the moment the question of whether an "electromagnetic device" of ***any*** kind that is suitable for aftermarket installation on a consumer vehicle has ***any*** capability to "sort molecules," which is terrifically suspect in and of itself.


For the sake of argument, let's say such a device exists, and that it is able to rearrange the molecules in the fuel flow in a way that is better suited for combustion. Let's further say it were technologically possible to put the "active portion" of the device, the part that "sorts" the molecules, right at the outlet of the fuel injectors. (This is of course impossible to achieve with an aftermarket device, but let's go with it for the sake of argument.) This would achieve "sorting" of the molecules right at that outlet orifice.


Molecules vibrate and rotate ***very quickly***. For example, [Wikipedia](https://en.wikipedia.org/wiki/Molecular_vibration) puts the temporal frequency for vibrations at somewhere between $10^{12}~\mathrm{Hz}$ and $10^{14}~\mathrm{Hz}$. At typical freeway speeds, automobile engines operate at around $3000~\mathrm{RPM}$, tops, or $50~\mathrm{Hz}$. This corresponds to a time-per-cycle of ${1\over 50}~\mathrm s$, or $20~\mathrm{ms}$.


Let's say that only a tiny fraction of the cycle elapses between when the fuel is injected and combustion occurs, something like $0.01\%$ of the cycle, which translates to $0.002~\mathrm{ms}$, or $2~\mu\mathrm s$. In this time interval, the molecules of the fuel will have vibrated literally ***millions*** of times:


$$
\left(2\times 10^{-6}~\mathrm s\right) \*
 \left({10^{12}~\mathrm{vibrations}\over \mathrm s}\right) =
 2\times 10^6 ~\mathrm{vibrations}
$$


Similarly, the molecules will have rotated, translated relative to one another, and *collided* with one another many, many times in that (unrealistically short) $2~\mu\mathrm s$ span of time before the spark plug triggers combustion. No matter how you look at it, **the fuel molecules would have long "un-sorted themselves" by the time ignition occurs in the cylinder.**


(Not to mention, all of those assumptions in the first two paragraphs are also totally bogus.)


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