Printer Friendly Version
E-mail this Article
In a recent Oak Ridge National Laboratory study, funded by the U.S. Department of Energy, researchers found that the condition of an air filter does not have a significant effect on fuel economy.
On older vehicles with carbureted engines, air-filter-condition does have an effect, but not to the degree previously believed. Newer vehicles monitor and adjust fuel delivery based on the amount of air available to the engine.
Though a restricted air filter has no effect on fuel economy, it does have an impact on engine-power output. Automakers recommend that air filters be inspected and replaced only as needed. This practice takes into account the wide variety of driving conditions a vehicle may encounter.
Visual inspection remains the most common means for determining the condition of an air filter. An accurate method is to remove the filter and hold it up to a 100-watt light bulb. If light passes through more than half of the filter, it can be returned to service. If major portions of the filter are blocked, the filter should be replaced.
