2011 Toyota Tundra Double Cab Owners Manual - Page 692

6-1. Specifications n If your engine knocks l Consult your Toyota dealer. l You may occasionally notice light knocking for a short time while accelerating or driving uphill. This is normal and there is no need for concern. n Fuel quality In very few cases, driveability problems may be caused by the brand of fuel you are using. If driveability problems persist, try changing the brand of fuel. If this does not correct the problem, consult your Toyota dealer. n Gasoline quality standards l Automotive manufacturers in the US, Europe and Japan have developed a specification for fuel quality called World-Wide Fuel Charter (WWFC) that is expected to be applied worldwide. l The WWFC consists of four categories that are based on required emission levels. In the US, category 4 has been adopted. l The WWFC improves air quality by lowering emissions in vehicle fleets, and customer satisfaction through better performance. n E85 fuel (Flex-fuel vehicles) l E85 fuel is a blend of 85% ethanol and 15% gasoline. However, E85 does not necessarily contain 85% ethanol. The ethanol content of E85 is required by ASTM to be between 70% and 85%. For example, in cold climates the ethanol content of E85 may be reduced during the winter months to maintain cold weather starting performance. l E85 has less energy per gallon than gasoline, so you will need to fill your fuel tank more frequently when using E85. l The number of fuel stations that sell E85 fuel is limited. For more information about fueling stations, please refer to the U.S. Department of Energy Web site. http://www.afdc.energy.gov/afdc/locator/stations/ n Toyota recommends the use of gasoline containing detergent additives l Toyota recommends the use of gasoline that contains detergent additives to avoid build-up of engine deposits. l All gasoline sold in the US contains detergent additives to clean and/or keep clean intake systems. 6 Vehicle specifications 669