Fuel Management

Mythbusters: Fleet Edition

November 2010, Government Fleet - Feature

by Tariq Kamal - Also by this author

Windsor Police Force’s Sgt. William Hunt Jr. presented “Mythbusters: The Snake Oil Saga” to a packed room of fellow fleet professionals at NAFA’s 2010 Institute & Expo.
Windsor Police Force’s Sgt. William Hunt Jr. presented “Mythbusters: The Snake Oil Saga” to a packed room of fellow fleet professionals at NAFA’s 2010 Institute & Expo.

It's easy to be tempted by claims that an additive can improve gas mileage or that changing certain parts more frequently will reduce engine wear. But is there hard evidence to back those claims?

Sgt. William Hunt Jr., manager of fleet and logistics for the Windsor Police Force in Ontario, Canada, presented "Mythbusters: The Snake Oil Saga," at NAFA's 2010 Institute & Expo. His presentation marked the culmination of two years of research and experimentation. Hunt's objective was to determine the validity of popularly held beliefs about products that purportedly boost or reduce fuel economy.

Hunt called two professors from the mechanical engineering department at the University of Windsor to oversee the lab work. Two Ford-certified master technicians employed by the Windsor Police Force drove more than 60,000 test miles in three vehicles: a 2000 4.8L V-8 Ford Crown Victoria Police Interceptor with 117,000 miles on the odometer and two 2005 Chrysler Sebrings with 65,000 miles and 41,000 miles, respectively, on 2.7L V-6 engines.

Claim: Full synthetic motor oil will increase fuel economy

Conclusion: Myth

Test Results: The Sebring with 65,000 miles covered 23.19 miles per gallon on conventional 5W-30 motor oil and 22.74 mpg on a full synthetic motor oil of the same grade — a decrease of 1.97 percent.

Notes: This is one case in which the oil maker's claims don't necessarily match the myth in question. Rather, the company that produces the full synthetic simply states that switching from mineral blends to a full synthetic can extend oil life — a claim that Hunt's scientists were able to confirm in lab tests.

Claim: Oil and fuel additives will increase fuel economy

Conclusion: Myth

Test Results: Running on the same conventional 5W-30, the team calculated a base mpg of 23.97 for the Sebring with 41,000 miles. The techs added the prescribed amount of a popular oil and fuel treatment but found no discernable gain in mileage, despite manufacturer claims to the contrary.

Notes: The manufacturer's pitch seems to focus on better fuel economy rather than the more verifiable benefit of reduced engine wear. If you're wondering why, don't ask Hunt. "It does extend engine life, but this was not part of the parameters," he said. "I would have been very happy if they had promoted that instead."

Claim: Performance-type air filters will improve fuel economy

Conclusion: Myth

Test Results: The Crown Vic logged 18.49 mpg with a factory-grade air filter. After replacing it with a leading performance-type aftermarket filter, the team found the big V-8's mileage had improved to only 18.5 mpg.

Notes: Hunt praised the filter manufacturer's marketing copy, which wisely relies more on personal testimonials than actual claims. On the company's Web site, one customer reports a 6 percent improvement in fuel economy on his light-duty pickup.

Claim: Fuel-line catalysts will increase fuel economy

Conclusion: Myth

Test Results: Much like the aftermarket air filter, equipping the Crown Vic with a fuel-line catalyst resulted in a less-than-negligible gain in fuel economy: 18.52 mpg with the catalyst against the 18.49 mpg baseline.

Notes: The catalyst tested is, for all intents and purposes, one or more hunks of metal alloy dropped into the gas tank or fuel line and left there, supposedly, to boost oxidation. Unlike the products tested in the first three myths, the manufacturer's Web site clearly states that adding the catalyst will result in an increase of at least one mile per gallon.

Claim: Older spark plugs will drastically reduce fuel economy

Conclusion: Myth

Test Results: The Police Interceptor was equipped with a fresh set of spark plugs for its control run; they were then replaced with a set with 62,500 miles of wear, resulting in a 1.4 percent decrease in fuel economy.

Notes: Hunt puts this one in the "myth" category because he personally predicted a dropoff of at least 5-6 percent. That may still be the case for older vehicles; however, Hunt's scientist friends told him the Crown Vic's 10-year-old onboard computer software was able to recognize the slower-firing plugs and compensate accordingly.

Claim: Dirty or partially plugged air filters will drastically reduce fuel economy

Conclusion: Myth

Test Results: Hunt's crew put duct tape over half of the Crown Victoria's already-used, factory-grade air filter for the initial run, then replaced it with a fresh filter. Adding the duct tape did nothing to compromise the car's fuel economy baseline of 18.49 miles per gallon, but replacing it with the new filter did. Running on a fresh-from-the-box OEM filter, the Police Interceptor logged only 18.3 mpg.

Notes: In another surprise for Hunt, a report from his mechanical engineers found the onboard computer worked hard to compensate for worn parts. "The spark plugs got me, but I figured there was no way this one would," Hunt said. He did note, however, the driver "noticed a lack of power" with the clogged and duct-taped filter installed.

Claim: Improper tire pressure will substantially reduce fuel economy

Conclusion: Fact

Test Results: Decreasing the Crown Vic's tire pressure from the factory-specified 32 pounds per square inch to 22 psi resulted in a dramatic decrease in mileage — 16.17 mpg versus the 18.49 mpg baseline.

Notes: Reducing the pressure by 10 psi might seem drastic, but from behind the wheel, Hunt's tech said he felt most drivers would not notice the difference. Due to the dangers inherent to driving on underinflated tires, Hunt limited the vehicle's speed to 50 mph for this ­experiment.

Tires filled with nitrogen retain their pressure better, keeping moisture out and ultimately extending tire life. But for small fleets, Hunt’s team couldn’t justify the cost of adding a proprietary fill station.
Tires filled with nitrogen retain their pressure better, keeping moisture out and ultimately extending tire life. But for small fleets, Hunt’s team couldn’t justify the cost of adding a proprietary fill station.

Claim: Replacing air with nitrogen in tires will increase fuel economy

Conclusion: Undetermined

Test Results: None

Notes: Hunt relied on interviews with scientists and other experts working in the fields of tire manufacturing, compressor supply, and mechanical engineering to determine the veracity of this claim. In the end, he declined to categorize it as "myth" or "fact," but did list the many known benefits of nitrogen fill versus regular air. He
also stated, however, that none of the 20 experts he consulted could justify the added cost for any fleet outside the military or aviation segments, and that none had filled their personal vehicles' tires with nitrogen.

In conclusion, Hunt says, "As a fleet manager, you really need to keep an eye on the world around you. You can make anything work in the lab, but when you put it in a real-world setting, you won't get the same results. Results will change both positively and negatively. In our tests, some products worked and some didn't work. The trick is to find the ones that work without spending a lot of money."


  1. 1. Al Thompson / Y3K Energy [ June 22, 2012 @ 12:44AM ]

    Re: Fuel Line Catalysts (the exception). There have been many fuel line catalysts, magnets and pellets that have not worked. Overall, your "Myth" assumption may be true (over-All), but you can not include the one in-line fuel catalyst that has been proven to reduce fuel consumption and emissions while increasing horsepower and torque in gasoline, diesel and propane-powered vehicles - The Fitch Fuel Catalyst. Besides passing the FTP/CVS-75 (improved fuel economy on a 6.6L GMC Duramax over 13%) and being tested and approved for installation on US Navy and US Air Force vehicles (the US Navy installed 10,000 units), the City of Allentown, PA tested, installed and assessed after one (1) year service of the Fitch Fuel Catalyst and reported in their Newsletter that they were pleased with the results and they made the right decision. Documentation is available. Too much to say and show in this post. INFORMATION: Al Thompson / Authorized dealer for the Fitch Fuel Catalyst - 310-497-1798, email: [email protected] Contact me and I will welcome an opportunity to provide you with more information. The Fitch Fuel Catalyst actually works as advertised.

  2. 2. John Cruz [ April 18, 2013 @ 10:58AM ]

    Al, can you give us links to support your claim please?

  3. 3. DB [ September 29, 2014 @ 04:53AM ]

    I can add a bit of info about the Fitch Fuel Catalyst:


    That's the military testing of the FFC, it's a PDF file. The blacked-out text can be copied/pasted to Notepad to read it.

    I'm not affiliated with Fitch in any way, and have yet to try the FFC (but I will be), but apparently it does have some effect upon fuel.

  4. 4. Dan Watson [ August 03, 2015 @ 05:54AM ]

    Am I reading this correctly that the test was ONE car (the Sebring) for the engine oil test for mileage? If you want to contest fuel economy claims then you should use ASTM mileage testing not a test of such low reliability. The smallest number of vehicles to even achieve any level of reliability would be 10 vehicles and this would be shaky. Then there are the number of variables that the ASTM testing tries to mitigate so some reliable level of testing results can be compared. I guess the best way to put this for police personnel is " the evidence is not scientific and would not be allowed in court"

    Also, all synthetics are not the same. Article after article in the lube industry warn of glorified petroleum being sold as synthetic. It is so bad that there is a move to develop a new identification for true synthetic oils so the consumer will not duped.

    Maybe I can get a complete description of all the testing materials and parameters of the test so I can review it and make further comments

    Dan Watson
    Certified Lubrication Specialist, STLE

  5. 5. [email protected] synthetic oil [ January 04, 2016 @ 10:09AM ]

    I was looking for some informative article to gain knowledge about synthetic oil.Then, iv`e found the above article and i`m really impressed.Synthetic oil saves our money, our machine, our environment(from pollution). From now on, i`m going to use synthetic oil for my car., Meanwhile, I`ve overviewed some review sites and among them bestsyntheticoilreviews.com seems helpful to me. Thanks for this awesome article.

  6. 6. Ed [ March 30, 2016 @ 07:19PM ]

    [email protected] synthetic oil...proclaiming how good bestsyntheticoilreviews is...seems legit.

  7. 7. Tony [ July 30, 2016 @ 06:00AM ]

    I would like to see information on fuel usage on trucks that install synthetic gear lube in their transfer case and differentials. I know from experience the benefits it has on wear, but what about fuel use? A friend of mine was racing a small sedan on road courses and the differential was so hot you could burn your hand on it, when we switched him to Amsoil gear lube it was MUCH cooler.
    The other point that was made concerning the air filters affect on performance vs fuel use, begs the question about the other products. Many want to know if acceleration and throttle response can be improved without sacrificing fuel use. In normal driving, when pulling into traffic, merging on to the interstate, etc. one is not always accelerating at optimal fuel economy. I contend that an increase in performance that has a marginal affect on fuel use might cancel each other out, as in the case of police fleets where many of the drivers are in a hurry to get where they are going, or just a bit more aggressive in their driving style.
    Thank you,

  8. 8. Peter [ January 07, 2017 @ 11:04AM ]

    I am a little late here but since this may be of help to others - The comment by DB, Sept 2014, suggests a link to a mil test of the Fitch Fuel Catalyst (www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA429975). DB then comments that he will be trying this unit implying that the mil report is positive. If you read the report, Section 3 Conclusions, it is clear that the reported testing showed zero benefit.

  9. 9. John Alexander [ February 07, 2018 @ 12:01AM ]

    Hello Peter, The facts are as follows,
    "The test was run on JP8 jet fuel which was part of a US Military program. We told the army we had no effect on but they insisted on running the evaluation. We went on to do additional research with the Department of Energy and University of Connecticut which resulted a very positive outcome. The US Navy and Airforce procured for over 11,000 pieces of equipment"
    From the manufacturers response to my question.
    The reason why the Catalyst does not work on Jet fuel is that there are additives that are added to the Jet fuel to prevent fuel freezing at high altitudes due to the cold temperatures. and this is a problem for the Catalyst


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