If certain grades of fuel are not preheated properly, what may occur?

When certain grades of fuel are not preheated properly, it can lead to poor combustion performance. Proper preheating is essential because many fuels need to reach a specific temperature for optimal atomization and combustion. If the fuel is too cold, it won't vaporize adequately, resulting in incomplete combustion. This often manifests as larger, unburned fuel particles that contribute to inefficient energy release.

As a consequence of poor combustion, there is an increase in the amount of fuel that is consumed to produce the same amount of energy. Additionally, incomplete combustion generates more pollutants, such as carbon monoxide and soot, which can further reduce overall efficiency. Therefore, the outcome is high fuel consumption coupled with poor combustion results.