What is the effect of alcohol on engine performance?

Alcohol can have a notable impact on engine performance, particularly when mixed with gasoline in varying ratios. One significant effect is that it can cause the engine to run lean. This occurs because alcohol, such as ethanol or methanol, has a different stoichiometric air-fuel ratio compared to traditional gasoline; it needs more air for combustion than gasoline does. If the fuel mix includes a high percentage of alcohol without proper adjustment to the air-fuel mixture, it can lead to inadequate fuel supply in relation to the air, hence the engine runs lean.

Running lean can result in higher combustion temperatures, which may lead to engine knocking and potential damage over time if not properly managed. It emphasizes the importance of calibrating the engine management system when alcohol is introduced into the fuel mix.

While alcohol can improve power output under some conditions or reduce emissions due to its cleaner burning properties, these effects can be variable and depend heavily on the engine design and tuning. It's essential to understand the specific dynamics of fueling when incorporating alcohol into engine applications.