What is most viscous petrol diesel gas kerosene bitumen?

Bitumen is the most viscous among petrol, diesel, gas, and kerosene. Viscosity refers to a fluid's resistance to flow, and bitumen is a heavy, tar-like substance with a high viscosity. In contrast, petrol and gas are lighter and flow more easily, while diesel has a moderate viscosity, higher than petrol but lower than bitumen. Kerosene sits between petrol and diesel in terms of viscosity.