Fuel Doctor - For automobiles, trucks, and buses Fuel Doctor's state of the art formulation converts free water and microbial growth to microscopic particles. Unique in the industry, having crafted their skills using day to day, hands on application, observation and orientation. Fuel Doctor promotes optimum performance, increased injector efficiency, maximum fuel economy and extended filter life. Fuel Doctor is specially formulated to dissolve and disperse gum and varnish deposits; prevent the accumulation of condensation in fuel and control fuel bug growth to protect the entire fuel system.