In recent years, fluoroelastomers have been used in automotive fuel systems with increasing regularity. Automotive fuels have become increasingly aggressive on fuel handling polymers. Gasolines blended with alcohols, alcohol by-products, and additives place a broader challenge on fuel handling polymers. Fluoroelastomers, especially high fluorine types, are viewed by many engineers as a method of stabilizing part performance in the face of today's ever-changing fuels.This paper will compare a traditional fluoroelastomer used in automotive fuel systems to new development fluoroelastomers that are designed to help both the end user and the rubber part manufacturer. The testing done will focus on benefits available from the new FKM polymers, such as low swell in fuel/alcohol blends, improved low temperature flexibility, and improved compression set resistance. Applications such as 0-rings and seals in fuel-injection systems and fuel handling tubing and hose are expected to benefit from these new FKM polymers.