Toyota FFV's are Flex Fuel Vehicles. They economize unleaded gasoline fuel use by also using E85 ethanol, but do not require any effort by the driver to switch between the fuels. As of 2010, Toyota offered certain models of its Tundra truck and Sequoia SUV as FFV's.
FFV's have some different mechanical components from their gasoline-only counterparts. They have larger-capacity fuel injectors and pumps to deliver larger fuel amounts, necessary due to the decrease in energy output of the E85 ethanol per same amount of volume. FFV's also have ethanol-resistant gaskets and seals.
Switching between E85 ethanol and unleaded gasoline does not affect a Toyota FFV's engine durability or its performance. The decreased reliance on gasoline fuel affects only the fuel economy of the car. No problems result from mixing ethanol and gasoline in the car's tank, because the FFV senses the ethanol/gasoline ratio in the tank and adjusts the engine's performance accordingly.
As of 2010, the warranty for FFV's is the same as that of the non-FFV's.
