What is the effect of high ethanol content in fuel on small engine performance?

High ethanol content in fuel can reduce the performance of small engines for several reasons. Ethanol has different combustion properties compared to traditional gasoline, including a lower energy content. This means that while ethanol can increase the octane rating of fuel, it doesn't provide as much energy per unit volume as gasoline does.

When small engines use fuel with high ethanol concentrations, they may experience issues such as reduced power output, difficulty starting, and increased likelihood of fuel system problems due to corrosion or phase separation. Additionally, ethanol can absorb moisture, leading to water in the fuel system, which can further degrade performance and cause engine misfires.

Thus, while ethanol can enhance certain properties of fuel, the overall impact on performance in small engines—especially those that aren't specifically designed for high ethanol content—tends to be negative. This is why the choice indicating a reduction in performance is the most accurate reflection of the effects of high ethanol content in fuel for small engines.