Bi-fuel refers to a system or vehicle that can operate using two different types of fuel. Typically, this involves a combination of a conventional fuel, such as gasoline or diesel, and an alternative fuel, like natural gas or propane. This flexibility allows for improved efficiency and reduced emissions, as the vehicle can switch between fuels based on availability and cost. Bi-fuel systems are commonly used in commercial vehicles and public transportation to enhance sustainability. By utilizing alternative fuels, these systems help decrease reliance on fossil fuels and contribute to cleaner air. Additionally, bi-fuel vehicles can often be refueled at existing gas stations, making them convenient for users.