In what condition should fuel tanks on power tools be left when not in use?

Leaving fuel tanks on power tools full when not in use is important for several reasons. A full tank can help prevent condensation inside the fuel tank, which can occur when there are fluctuations in temperature. Condensation can introduce moisture to the fuel system, leading to potential fuel contamination and engine performance issues.

Moreover, a full tank of fuel ensures that the engine is protected from any possible evaporation or degradation, which might happen with lower fuel levels. Fuel that sits for extended periods can break down or the volatile components can evaporate, making it less effective when you are ready to use the tool again.

Additionally, a full tank minimizes air exposure, which can lead to oxidation and deterioration of the fuel quality. It is essential to ensure that the fuel is kept in the best condition possible to maintain the tool's reliability and performance when needed.

In contrast, other options may leave the tank susceptible to issues like moisture buildup or fuel degradation, which could affect the tool's functionality when it is next used.