Do Plastic Fuel Tanks Deteriorate?

The longevity and reliability of plastic fuel tanks have been a topic of concern for many car owners. This article delves into the specific issues these tanks face when used with certain types of fuel, such as ethanol, and explores how environmental factors like sunlight can impact their condition over time. Additionally, it provides practical advice on how to extend the life of your plastic fuel tank.

The Impact of Different Fuels on Plastic Fuel Tanks

Plastic fuel tanks, commonly found in modern vehicles, are generally durable and effective. However, they are not immune to deterioration. One of the significant issues arises when these tanks are used with ethanol-based fuels. Ethanol, due to its chemical composition, can begin to erode through the fuel tank material. This problem is not limited to modern vehicles; even older cars that have rubber fuel tanks can face similar deterioration when exposed to ethanol. Regular maintenance and careful handling can minimize this risk, but it is still an important consideration for car owners.

Corrosion Issues in Modern Cars

While plastic fuel tanks offer superior resistance to corrosion compared to their rubber predecessors, they are not invincible. The Environmental Protection Agency's (EPA) strict regulations on the use of zinc and lead in modern vehicles has significantly reduced the availability of rustproofing methods that do not compromise on cost or performance. As a result, any metal components attached to plastic fuel tanks, such as the metal rings used in Dodge trucks to attach the fuel sender, are more prone to rust and eventual failure. This is especially true for items exposed to the elements, such as brake lines and metal frames, which can rust away more easily due to environmental exposure.
The solution lies in using alternative materials and advanced coatings. Feritic nitride coatings, for example, provide a cost-effective and highly durable rustproofing solution. However, these solutions may be more suitable for industrial use than for the average car owner due to their cost and technical requirements.

UV Rays and Fuel Tank Exposure

Another factor that can cause plastic fuel tanks to deteriorate is exposure to sunlight. Ultraviolet (UV) rays, which penetrate the tank's coating, can accelerate the aging process, causing discoloration and deterioration at the edges of the tank welds. This exposure can lead to the leaching of harmful substances into the fuel stored within the tank. It is important to store your car in a shaded area or use a fuel stabilizer to protect the fuel quality and extend the life of the plastic tank.

Replacing or Rotating Fuel for Long Term Storage

For those who engage in long-term storage of their vehicles, the integrity of the fuel itself is crucial. Plastic fuel tanks are recommended for short-term storage as they can last up to 5 years under normal conditions. However, the fuel stored in these tanks has a much shorter lifespan, lasting only about 1.5 years before it degrades significantly. For long-term storage, it is advisable to either replace the fuel every 6 months or use fuel stabilizers to extend the fuel's lifespan. Another option is to convert the vehicle's fuel system to metal tanks, which have a much longer lifespan and are less susceptible to deterioration from exposure to ethanol and sunlight.

Conclusion

In summary, while plastic fuel tanks offer numerous advantages over their rubber counterparts, they are not immune to deterioration. Factors such as the type of fuel, environmental exposure to UV rays, and proper maintenance can all play a role in extending the life of your plastic fuel tank. For long-term storage, regular fuel rotation or stabilizer use is crucial to maintain your vehicle's performance and reliability. Understanding these issues can help car owners make informed decisions to protect their vehicles and ensure they remain in optimal condition for years to come.