Which type of engine is known to produce more pollution?

Older two-stroke engines are known to produce more pollution primarily due to their design and operational characteristics. These engines burn a mixture of oil and fuel, which not only leads to higher emissions of hydrocarbons but also results in unburned fuel being released into the environment. The combustion process in two-stroke engines is less efficient than in four-stroke engines, meaning that more emissions are created for the same amount of work done.

In contrast, electric engines have no tailpipe emissions at all, making them one of the cleanest options available. Four-stroke engines generally operate more efficiently and completely than two-stroke engines, leading to lower emissions. Hybrid engines, which combine an internal combustion engine with an electric motor, strive to reduce overall emissions by optimizing fuel use. Thus, the inefficiency and pollutive nature of older two-stroke engines distinctly mark them as a significant source of pollution.