The location and design of fuel tanks must not take up the vehicle's space. Most auxiliary fuel tanks are situated on the rear portion of the vehicle. To prevent the fuel from splattering into the fuel system of the car, internal baffles are used. Defect in the baffles can be determined if noises are heard on the rear part of the car especially when adding or decreasing speed. Fuel filler pipe, fuel outlet line and a vent system are standard components of all fuel storage tanks. Filler pipe prevents the leaded fuel from entering the fuel system. Fuel lines are made up of elastic hoses and steel lines to transport the fuel from the tank to the engine. Any tool made of copper or aluminum must not be used when having steel lines repair or replacement. The rubber hose must be replaced with high-quality materials since ordinary rubber can be easily subjected to wear and tear.
As product of technological advances, plastic can now be used as component for fuel tanks. Plastic fuel tanks are used nowadays in various applications because of its flexibility. It can be molded in different shapes and forms, has stronger resistance against corrosion and puncture, lighter in weight and cheaper compared with other materials used. New technologies are used to improve the capacity of plastic as fuel tanks. Fire resistance is one of the aspects to be improved. Plastic fuel tanks can melt when exposed to fire which can cause fire as the fuel content flows out. Modern marine fuel tanks have crosslinked resin which does not melt when exposed to too much heat. Another solution developed is to use intumescent coating on the exterior surface of the plastic. Exposure to fire changes the intumescent covering into a bulky layer that can protect the plastic. The layer prevents the fire from heating up the tank.