Selecting the correct material is critical for safety and longevity. For petroleum and fuel, carbon steel is the standard due to its cost-effectiveness, while aluminum alloy is preferred for its lightweight properties, which increase payload capacity and fuel efficiency. For chemical or food-grade liquids, 304 or 316L stainless steel is mandatory to prevent corrosion and ensure hygiene compliance. Always verify the tank wall thickness (typically 5mm to 8mm) to ensure it meets pressure requirements.