Fuelshark Wants Us To Apologize Because They Sell Bullshit

A couple months ago I reviewed a remarkable-sounding product called the Fuelshark, a simple plug-in device for your car that claimed to improve gas mileage. I did some tests, took it apart, and found their claims to be bullshit. Well, the Fuelshark people finally got around to reading it, and they're pissed. They want me to apologize.


Okay, fair enough. I'll say I'm sorry. Here we go:

I'm sorry you sell a product that's clearly bullshit.

There! Are we all friends now? Who wants a hug?

Actually, I think what happened is that someone at Fuelshark must have realized that if you Google "Fuel Shark" my story comes up first, even before their own site, and if you Google "Fuelshark" it comes up second, right after their site. I'm going to go out on a limb and guess they're not crazy about that.

In fact, they were pissed enough to send us this letter:

I am the manager for the owners and makers of the Fuelshark. Jason Torchinskywas initially contacted by our Public Relations firm last November and they sent him a sample of our product along with testing procedures. After receiving the sample, Jason e-mailed our Public Relations firm asking certain technical questions on Friday December 6, and we initially responded to him right away stating that there were time zone differences with our technical people in China and we would respond as quickly as possible which would be the first part of the following week as everyone was gone over the weekend. On Tuesday December 10, we were prepared to respond to his e-mail regarding the farads issue he had questioned us about. As we were getting it ready to send to him, I received a tweet showing that Jason had just published an article on Jalopnik.com about the Fuelshark even though he had not yet received our response to his technical questions. The headline reads "The Fuelshark won't save you gas because it runs on Bullshit".

I have attached the document that we were prepared to send Jason on Dec. 10. As you will see, the capacitor's farads have nothing to do with how our product functions which is the basis of Jason's article, so the article is not correctly stating how our product works. Now that we have had a chance to read the article, I would also like to add that the Fuelshark is designed to work on vehicles that are more modern as they are equipped with more electronic components, and fuelinjectors. The 1973 VW Beetle he used our product on is too old as its electrical system is very basic unlike newer cars. In addition, it does not use fuel injectors.

We request that the article be removed from your website(s) and internet search engines as it incorrectly states how our product works and is damaging to our brand. We also noticed that some other websites are running this article. Are these also your websites?

Lastly, since this article was tweeted by either Jason or Jalopnik, it would be appropriate for Jason or Jalopnik to send a tweet regarding the removal of this article because it incorrectly states how our product works along with "our apology to @fuelshark".


There's a lot in there that needs addressing, so let's get right to it.

First of all, let's address the claim that I somehow misrepresented the way the Fuelshark works in my review. Since the product doesn't actually do anything, this is a tricky claim to make. At no point in the article did I ever say the Fuelshark worked in any particular way — the components of the Fuelshark are incapable of performing any actual function relating to the operation of a car beyond lighting a blue LED. What I was intending to show was that the Fuelshark does not work in the way described on both the package and from correspondence with Fuelshark itself.


There's actually two ways the Fuelshark package and press materials claim the Fuelshark works. The one I focused on in the original article was this method:

... supplementing the required voltage for devices such as lights, stereos, power windows, etc. By using the Fuelshark, your car's battery does not struggle to provide the additional power needed to operate these devices.


That's right on the box. In addition, the president of Fuelshark, Clay Renshaw, sent me this explanation:

Capacitors are now being used by auto makers to store and release energy in order to improve MPG. Mazda has introduced this in their SkyActive I-Eloop system using a 25 Volt capacitor. We use a 35 Volt capacitor. Article attached (Nov27 Mazda).


Keep in mind, I didn't pull this ex recto — the president of Fuelshark himself, his majesty, sent me that description. What I did do was point out that the capacitor that Mazda uses for the system Fuelshark was comparing themselves to has 120,000 times the capacity of the capacitor in the Fuelshark. Which is one reason why it works and the Fuelshark just loiters in your cigarette lighter, like some forsaken blue-glowing buttplug.


So now Fuelshark is saying that the way their product supposedly works — one of the ways printed on their package, referenced on their website, and told to me directly by their president — isn't how their product works. Of course not! How could I have made such a foolish mistake?

Happily, the good folks at Fuelshark told me the real way the Fuelshark saves you "up to 10% or more" on gas. Here's the entirety of what they sent:


An electrical noise filtering unit's performance is measured in two ways; capacity and impedance. With regard to high frequency noises occurring as short electrical impulses, the impedance is what is most important. Low impedance in the filtering results in better noise filtering.

The Fuelshark uses a low ESR capacitor. By using this type of capacitor, we have a low impedance filtering circuit. This can accept and absorb high frequency electrical distortions. These distortions can have an effect on the electronic systems of a vehicle. Thus, the capacitor is being used as a voltage stabilizer.

The purpose is to optimize the vehicle and smooth the current as evidenced in the automobile voltage graph below. The 1000uf 35V high ripple current capacitor we use has impedance that is very low. It can absorb the electrical noise at high frequencies and convert them into voltage.

Ignition systems, blower speed controllers, fuel injectors, among other things can cause high frequency, low current spikes or dips. Most of the noises that affect a vehicles electronic systems and accuracy of the sensors as well as spark performance are the result of these spikes. These spikes can be eliminated by using a capacitor as the capacitor can charge and discharge at high frequencies up to 100KHz. With regards to transient dips, the capacitor cannot eliminate these dips, but can be helpful in reducing them.

The effect on electronics is the improved operation and precision of electronic control devices (optimal operation of ECU, TCU, sensors, electric power steering, etc.). It also improves operation of other noise sensitive electrical devices (audio system, etc.).

The alternator, battery and other electronic devices may have an increase in lifespan due to the reduction of harmful electrical distortions. Our capacitor has 3000 to 6000 hours of lifespan thus the recommendation to replace the unit once every 3 years. 3 years replacement was determined using the assumption that drivers average 3 hours per day driving their vehicle and assuming the 3000+ hour capacitor lifespan to stay on the safe side.


Along with that text, they also sent this pleasingly technical looking set of graphs:


Let's address these graphs first, since they sort of set the tone for everything. Look at the graphs carefully. Notice anything missing? Looking carefully, you may be able to note the absence of something scientists call "any information at all."

There's no context whatsoever for these graphs — there's no numbers, no scale, no nothing. It is a graph that shows generally, what filtering capacitors do, given an input that varies in voltage. Here, look, you can find the same basic graph here on this basic electronics education site.


Saying this ridiculous chart somehow says anything about how the Fuelshark interacts with your car is like showing a picture of a driveway gravel and saying it explains Olympus Mons on Mars. Yes, they're both fundamentally made of rock, but the context and scale and everything are not even remotely related.


Just the inclusion of this chart in all this pisses me off, because it suggests that whoever they send this document to is such a drooling simpleton that the inclusion of any wiggly lines on an X-Y plot will make their brain essplode and then they'll believe any bullshit.

So, Fuelshark now claims that they're able to get your car to save gas by "filtering" the electrical system, which will magically improve your engine's efficiency. I had to look pretty hard to find an engineer willing to evaluate this in detail; almost every engineer I sent this to didn't even feel it was worth taking seriously at all. It would be like if I was trying to find a Rabbi who could help me disprove that Chuck-E-Cheese was the primary antagonist in the Book of Job — how can you debunk something that's so clearly horseshit?


Happily, I did find someone to indulge me, and one not under the thumb of the big car companies who might try to keep a revolutionary idea like the Fuelshark down: Professor Joseph Shepherd of Caltech, professor of Aeronautics and Mechanical Engineering, as well as a gearhead. Here's what he told me when I read the description Fuelshark sent me:

"Nonsense. It's total nonsense."

Happily, he elaborated further:

"If there's noise in the electrical system. car makers have been filtering that out for over 50 years — and, that's been mostly to keep buzzing noises from coming out over the radio. The electrical system makes a modest load on the engine and has very little to do with fuel economy at all. Whatever fractional amount of load it puts on, saying that filtering will get around 10% or more better MPG is absurd."


And that's all assuming the Fuelshark does any appreciable filtering at all, which it doesn't. For one thing, Prof. Shepherd said the car's battery does the lion's share of the voltage filtering as it is, and what's more, a capacitor set-up plugged into the 12V outlet like in the Fuelshark wouldn't work that way:

"A capacitor is passive. The cap starts discharged, you turn on engine and the cap gets charged up with 12V and stays charged. It took electrical energy to charge it, and it just sits there at 12v — not going back into the system or anything. You cut the car off and it discharges. That's it."


And, keep in mind, it was pretty indulgent of this guy to even go into this in as much detail. To most people familiar with car electrical systems, the idea is simply too ridiculous to even consider. My friend Tom Jennings, who helped me evaluate the Fuelshark in the first article, told me this when I asked him about testing:

There is nothing to test, even 10,000,00,000 microfarads stuck in a cigarette lighter socket would not have any effect on car operation, so their cap will do nothing. I reiterate, their [Fuelshark] actually *consumes* energy (the LED). It adds literally nothing. There's nothing to test.


And, speaking of testing, Fuelshark's claim in their letter that my test on my 1973 Beetle is invalid is, to be repetitive, bullshit. They told me over the phone that testing on the Beetle would be fine, and their own packaging says it works on any 12V car, and makes no mention of carburetors or fuel injection or whatever. Here's a quote from the site's FAQ:

Can I use my Fuelshark on any vehicle?
Yes, as long as the vehicle runs on a 12 or 24 volt system (most vehicles do).


That would seem to suggest that Fuelshark's claim that

Fuelshark is designed to work on vehicles that are more modern as they are equipped with more electronic components, and fuelinjectors. The 1973 VW Beetle he used our product on is too old as its electrical system is very basic unlike newer cars. In addition, it does not use fuel injectors.


... is some new criteria they just now decided. Plus, it makes even less sense if Fuelshark really believes that the Fuelshark does any filtering, since a vintage VW's electrical system is about as rough and unfiltered as you can get, and if a filter were to do any good at all, you think it'd be there.


So, even with this whole new way Fuelshark claims their product works, I think we can comfortably think of it as an exciting bit of fiction about how their product doesn't actually do anything. In light of this new data, however, I am willing to update my original claim that you'd get the same results plugging an olive into your 12V outlet. I now also believe a grape would work just as well.

So, if it doesn't actually work, how has Fuelshark managed to sell the many thousands of these things they claim they've sold? There's a few reasons. First and by far most importantly, fuel economy is notoriously hard to test accurately. There's so many factors that can affect a car's fuel economy that have nothing to do with the car itself. That's why the EPA tests fuel economy in a special laboratory where they can control as many variables as possible. And they don't trust the car's fuel gauge — they measure the amount of carbon in the exhaust. Really accurate MPG testing is not something a normal consumer can do.


There's also likely a small placebo effect from that blue light on your dash, reminding you to take it easy and save some gas since you just spent $40 on that thing. Of course, the opposite could be true, where you think, hey, I spent $40 on this magic gas-saver, I can go nuts!

So, without the ability to really accurately measure MPG, if someone really wants to believe the Fuelshark works, they can probably find at least a few numbers to back that up, regardless of whether or not the thing does anything at all.


Even so, I'd like to reiterate that based on my own tests, evaluations of the internals of the product, and consultation with experts, the Fuelshark does absolutely nothing beyond casting a novel blue glow in your footwell. I have found Fuelshark's multiple claims of how their product works to be contradictory and surprisingly fanciful. I'm not sure if they genuinely believe it works in the way they've described, or if they're just hoping that enough technical jargon and hand-waving will make people just accept it as truth.


The big question remains, though: why did they send me one in the first place? If I was selling this product, I'd keep it as far away from journalists and scientists as possible.

(Image credit: Olympus Mons painting from here.)

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