As a crucial energy carrier, waste cooking oil poses a significant threat to land and water resources. Furthermore, there is a risk of its reintroduction into the restaurant system, posing a direct threat to public health. Hence, converting waste cooking oil into clean energy has emerged as a pressing concern. This study compares the CO2 emissions and economic benefits of two pathways applied to automotive energy consumption——the waste cooking oil produced biodiesel pathway and the waste cooking oil mixed with coal for power generation pathway. The results show that for both diesel and electric versions of the same brand of vehicles, the CO2 emission of an electric vehicle using waste cooking oil mixed coal produced electricity is 0.181 kg/km, which is a 26.12% reduction compared to a diesel vehicle using waste cooking oil converted to biodiesel. Consumers appreciate the low price of electricity. However, for producers, the waste cooking oil produced biodiesel pathway demonstrates superior economic benefits. At the current market price, converting waste cooking oil into biodiesel will result in a net gain of 112.89 billion Yuan for the producer, whereas the waste cooking oil mixed with coal for power generation pathway will result in only 2.08 billion Yuan in net gain. This disparity is primarily attributed to the lower electricity prices for electric vehicles. To encourage the widespread adoption of waste cooking oil energization technologies, Chinese government can raise electricity prices for electric vehicles to a minimum of 1.599 Yuan/kW·h, ensuring equal net gains in both pathways.