air con costs

[bennybones]

does it cost more/use more fuel to use your air conditioning or is this a myth ?? I have a megane scenic does it differ from car to car ??

[colin6789]

Yes, the air con will use some power, but at normal speeds it is a small amount of the total enginr output and if you open the windows the increase in drag may cause more increase in fuel consumption. In traffic it may cause more fuel to be used.

[kempie]

Temperature, vehicle speed, vehicle size, and wind velocity and direction are all factors that will affect drag related increases in fuel consumption when windows are open. However A/C uses a significant quantity of fuel (I would hardly call a 10%-20% reduction in fuel economy as a "small amount") and for many cars A/C is demonstrably less fuel efficient than open windows even at speeds in excess of 60mph.

http://www.competetoconserve.com/blog/2008/08/ air-conditioning-vs-rolling-windows-down-the-f uel-efficiency-debate/comment-page-1/

http://the-grayline.com/2008/11/14/air-conditi oner-and-fuel-consumption/

http://wheels.blogs.nytimes.com/2008/07/30/the -air-out-there-an-endless-windows-vs-air-condi tioning-debate/

[Gadget004]

It does cost more in petrol as your engine has to drive the compressor which is an additional load. More load = more petrol.