Editing Engine (section)

==== Environmental effects ====
The operation of engines typically has a negative impact upon [[air quality]] and ambient [[noise pollution|sound levels]]. There has been a growing emphasis on the pollution producing features of automotive power systems. This has created new interest in alternate power sources and internal-combustion engine refinements. Though a few limited-production battery-powered electric vehicles have appeared, they have not proved competitive owing to costs and operating characteristics.{{Citation needed|date=November 2012}} In the 21st century the diesel engine has been increasing in popularity with automobile owners. However, the gasoline engine and the Diesel engine,  with their new emission-control devices to improve emission performance, have not yet been significantly challenged.{{Citation needed|date=November 2012}} A number of manufacturers have introduced hybrid engines, mainly involving a small gasoline engine coupled with an electric motor and with a large battery bank, these are starting to become a popular option because of their environment awareness.