Fuel-resistant plastics

Without plastics, automakers would have been hard pressed to develop fuel systems that simultaneously withstand aggressive fuels, reduce vehicle weight, aid impact resistance, and enable complex geometries. Furthermore, given the complexity of fuel systems, changes in one area often a ect other areas. This is the case when hot fuel from the engine compartment is returned to the tank. Plastic was introduced for fuel tank construction to improve chemical resistance and impact, and to enable tighter auto layouts versus steel tank designs. However, fuel temperatures rose sharply higher in the plastic tanks, because plastic is a good insulator, and because tighter layouts reduce the air ow that dissipates heat. As a result, fuel temperatures in tanks may reach 65°C (150°F) in plastic tanks, versus about 40°C (105°F) in steel tanks, and can rise to 120°C (250°F) or more in the engine compartment. The higher temperatures also make fuel more reactive and require more stable plastics.