Emission control

Vehicle emission control studies reduce the emissions produced by motor vehicles, especially internal combustion engines.

Engine efficiency has been steadily improved with improved engine design, more precise ignition timing and electronic ignition, more precise fuel metering, and computerized engine management.

Advances in engine and vehicle technology continually reduce the toxicity of exhaust leaving the engine, but these alone have generally been proved insufficient to meet emissions goals. Therefore, technologies to detoxify the exhaust are an essential part of emissions control.

Alternative fuel vehicles

Exhaust emissions can be reduced by making use of clean vehicle propulsion. The most popular modes include hybrid and electric vehicles.

As of December 2020, China had the world’s most extensive stock of highway-legal plug-in electric passenger cars with 4.5 million units, representing 42% of the world’s supply of plug-in vehicles.