Avgas, short for aviation gasoline, is a specialized fuel designed for use in piston-engine aircraft. It is formulated to provide high performance and reliability at various altitudes, ensuring safe operation of aircraft engines. The most common types of avgas are 100LL, which is low-lead, and 100, which contains higher levels of lead. Unlike regular gasoline used in cars, avgas has a higher octane rating, which helps prevent engine knocking. It is essential for maintaining the efficiency and longevity of aircraft engines, making it a critical component in the aviation industry.