Scrutinizing Snake Oil

There is an overabundance of products on the market that make various claims about improving fuel economy by simply adding this or that to the tank or the fuel system or somewhere else on the vehicle. The question is: Do these products work?   That uncertainty, along with addressing some common vehicle service myths, was the subject of the "Mythbusters: The Snake Oil Saga" session conducted during the NAFA Fleet Management Association 2010 Institute & Expo (I&E) that took place in Detroit, MI, last month.   NAFA is a not-for-profit, individual membership professional society serving the needs of members who manage fleets of automobiles, SUVs, trucks, vans and a wide range of specialized mobile equipment for organizations across the globe. The I&E is the association’s annual meeting that brings together fleet industry professionals from across North America for four days of education, trade show experience and networking.   Sgt. William R. Hunt, Jr., fleet and logistics manager for the Windsor Police Service in Windsor, Ontario, Canada, presented the results of testing and research he did with the help of noted engineers and scientists in North America.   The project involved three cars and 60,000 on-road test miles and considered a variety of commonly available products and their claims. Here are the highlights of the findings:   - Full synthetic motor oil will increase fuel economy. Hunt’s testing found that this was not the case, although synthetic oils did help engines run cleaner.   - Oil and fuel additives will increase fuel mileage. No so, but such additives did help extend engine life by reducing carbon deposits.   - Aftermarket performance type air filters increase fuel mileage. The testing also dispelled this claim. However, because such filters are designed not for normal driving but for use with "working" engines, they did show some fuel economy improvement in vehicles pulling heavy loads or, in the case of law enforcement vehicles, when in pursuits.   - Aftermarket fuel line catalysts will increase fuel mileage. No change in fuel economy was found from using fuel line catalysts.   - Old spark plugs will drastically reduce fuel economy. They did not. According to Hunt, onboard diagnostic systems compensate to provide the anticipated fuel economy.   - A dirty or partially plugged air filter will drastically reduce fuel economy. No. Here again, the OBD systems compensate for air flow restriction.   - Improper tire pressure will substantially reduce fuel economy. Yes. As part of the testing, tire pressure was reduced from 32 psi to 22 psi. This resulted in a 16.3 percent decrease in fuel economy.   - Is nitrogen cost-effective in optimizing fuel economy in fleets? No. While no testing was done, Hunt said the research found that nitrogen inflation would have no benefit to most fleets for several reasons. Key among them is that it is next to impossible to purge tires and get 98 percent nitrogen content - the percentage required for maximum benefit.