Poor fitting fuel caps can cause these problems

A gas cap that doesn’t fit right is a hazard to the owner and the environment in the following ways:

1. It allows fuel to evaporate and escape the gas tank and pollute the environment.
2. The efficiency of the fuel can be reduced — sometimes by as much as two percent.
3. It can allow dirt, debris and other contaminants to enter the gas tank. These contaminants can degrade the fuel and cause harm to other parts of the vehicle.