Gasoline blended for high-performance engines, often designated as 93 octane, can contain varying amounts of ethanol, typically between 10% and 15%. This biofuel additive is primarily derived from corn or other plant sources. A common blend includes up to 10% ethanol (E10), but some regions permit or even mandate higher concentrations, like E15 (15% ethanol). Specific regulations and fuel formulations vary by location and may be influenced by factors like altitude and season.
The inclusion of ethanol in high-octane gasoline serves several purposes. It acts as an oxygenate, promoting cleaner combustion and reducing emissions of certain pollutants. It can also enhance octane rating, crucial for preventing engine knock in high-compression engines commonly found in performance vehicles. The increasing use of ethanol blends is partly driven by renewable fuel standards and initiatives to reduce reliance on fossil fuels. Historically, ethanol content was lower, but advancements in engine technology and environmental regulations have supported greater integration of this biofuel.