Review: Testing the Fuel Shark MPG Enhancer


Fuel Shark Review

For just $39.95, the Fuel Shark promises that you’ll get 10% better fuel economy, better emissions, more horsepower, and a longer battery life- just by plugging a little dongle into your car’s 12V power outlet. Having spent more than few years, by now, working with heavily intelligent people who spent hours, weeks, and months hacking into the ECUs of Mercedes and Porsches in a bid to just see what was going on in there- let alone tune the things!- you might say that I was a little bit skeptical.

Still, one can be both skeptical and hopeful. So it was that, this past Thanksgiving weekend, I plugged the Fuel Shark (provided by Fuel Shark, for the purposes of this review) into the Chevy Cruze diesel‘s outlet …

Fuel Shark Test

… and started off on the 330-ish mile drive home.

So, using the scientific method of “filling up the gas tank like, right at the start of the drive” and heading out along the identical route (careful, I should add, to make stops that the same rest stops along the way), the Chevy Cruze’s on-board MPG calculator claimed 43.1 MPG on the return drive … which was a bit below what I saw on the drive out, which was Fuel Shark free. Weirdly, I showed a little over half a tank of gas left, compared to a little under half a tank on the drive out.

So- yeah. No matter how you slice those results, there was no 10% gain- which begs the question: is the Fuel Shark bulls***? I’m not ready to say it is, but I tried it again this past weekend in a 2014 Toyota Avalon, and got similar “nothing” results. That said, I have a few uncles who are tough to shop for, and they eat this “As Seen on TV” s*** up, so maybe I’ll be a Fuel Shark customer, even if I’m not a believer.


Original content from Gas 2.

About the Author

I’ve been in the auto industry 1997, and write for a number of blogs in the IM network. You can also find me on Twitter, at my Volvo fansite, or chasing my kids around Oak Park, IL.

  • Jason Carpp

    If it looks like a duck, swims like a duck, quacks like a duck, guess what? Anyone can advertise something on tv and claim that it helps to improve the mileage of a car or truck, but without real world testing, how can they know for sure?

  • AnEngineer

    This product claims it saves fuel by ‘balencing’ your cars voltage… I dont see how the engineers in charge of the electrical system somehow forgot to regulate voltage spikes… on every car… from every manufacturer.. ever.. and that this unregulated voltage can cause a 10% waste in fuel. This product sounds like a scam. And I don’t like it.

    • Jason Carpp

      I agree. I’ve learned over the years not to believe everything you see on tv advertisements.

      • Except the Magic Bullet. That thing is amazing.

  • Has anyone credible out there found a positive result?

  • Bob_Wallace

    If it worked…

    Major car manufacturers would have already incorporated this technology into their new models in order to help them meet new mileage requirements.

  • Bi-Polar Bear

    Ah hah hah hah! That is some funny chit right there. Reminds me of the good ol’ days when we car guys used to peruse the JC Whitney catalog, where just about every product claimed Faster starts! Better fuel mileage! Longer engine life! Reduced wind resistance! and Greater power!

    Not one of them worked. I should know. I bought most of them! And burned up a lot of gas testing them all. Perhaps the biggest scam was the “water injection system” which was nothing more than a plastic bottle you filled with a special liquid, aka windshield washer fluid. It had a vacuum hose that you plumbed in to the intake side of the motor using a spacer that fit under the carburetor. That one actually reduced gas mileage. %$#%^%#^&

    So thanks, Jo, for this valuable consumer research. As one wit has observed, “You’ll never go broke underestimating the intelligence of the American consumer.” ( : ~ >)

    • That injection system you mention is pretty similar to a lot of the methanol injection kits on eBay these days. Done right, a system like that can help you build boost and build big horsepower … done wrong, and 99% of them are done wrong, and you just burn more gas and toxify your emissions.

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  • Quite impressive post thanks for share……….

    • Thank you, gas safety spambot. I appreciate the pageview.

  • Abdul Saleh

    ermmmm.. it work on my car. proton preve 1.6 cvt.
    without shark.. 7.9l/100km
    with shark 7.0l/100km
    average 90mph driving
    just $5 in malaysia.. true story..
    it just 2200uF/25v capicitor in it..

  • Anonymus

  • Andy Roid

    Did you try opening it up? It’s literally just a wire that connects from the power supply to the LED. That’s it. No other components.