What is the purpose of adding urea solution to trucks?

[Aliyah]

Trucks add urea to purify exhaust emissions. Vehicles equipped with diesel engines generally require urea for exhaust purification. Here are several key differences between gasoline and diesel engines: 1. Gasoline engines have spark plugs; diesel engines do not. 2. Diesel engines are more efficient than gasoline engines. Although diesel engines generally have lower power output compared to gasoline engines, they produce higher torque. 3. Diesel engines also have better fuel economy than gasoline engines.