How much gas do car functions waste?

usually you only use 25% of the gas and the remaining goes out as gas poison like C02

It is hard to figure the percentage.The radio and head lights use very little fuel I doubt you can ever tell the diff.The air cond uses a measurable amount,but if you are really wanting to save gas have car tuned up keep air pressure in tires correct.

ur actually better off running ur ac unless u want to drive around in the summer with ur windows up thats what saves u gas other than that nothing that u mintioned will help really a few ways to help improve gas milage is a clean air filter proper plugs always use oem and properly inflated tires trust me i work on cars all day long and ive heard and tried most of it and nome of it works

A/C, 10-40% depending on the type and age of the car, and the fuel economy it gets. For instance a Camaro and a Geo Metro have about the same size cabin, so they take about the same energy to cool… but that’s a bigger bite out of the Geo’s fuel economy than the Camaro’s.

Headlights take 70 watts low beam and 110 watts high beam, its effect on fuel economy is probably too small to measure.

Factory radios take even less then headlights. If you have one of those insane THUMMBA THUMMBA aftermarket jobs, with the separate amps and battery just for the radio, then it could be as bad as A/C.

The headlights or electronics
& power windows do not affect the gas usage.
The A/C uses more gas when you use it.

It also depends on the road conditions. Rougher roads rob more gas milage. Your tires have to properly inflated.
& you have to keep yhour windows up cuz down windows create wind resistance.
Thank you so much for conserving gas. That’s what all americans should be doing to keep gas from hitting $4 a gallon.

radio and head lights basically 0 percentage, air conditioning only about 2-5 % maybe,it doesnt cost that much to run the air in a car,running with the widows down uses more gas,because it creates a drag on the car,you actually save by using the air in hot weather,for no more than what you will save from not using any of these features it wouldnt hardly be noticeable,i use mine,its worth the extra gas just to keep from not buring up all the time,good luck hope this helps.

Running A/C all the time would use 25-50% more gas

Do you do more highway or city driving? Here’s why: if you run the a/c around town, yes it will definitely use more gas, but if you open your windows on the highway the wind drag will cause you to use more gas. If it is not too hot then open your windows around town, but run a/c on the highway. By the way the “vent” feature on your a/c does not run the compressor, which pretty much eliminates the extra gas usage. It is the compressor which the engine has to run that causes the car to use more gas and get slightly worse acceleration. Running your headlights and radio has NO effect on your mileage, the engine’s electrical system is very well equipped to run these two (stock) systems without causing any strain. A very overpowered stereo system could cause a strain on your alternator and battery, but you would still probably never notice it at the gas pump.

http://www.dailyfueleconomytip.com/?p=370

http://articles.moneycentral.msn.com/SavingandDebt/SaveonaCar/20waysYouWasteMoneyOnYourCar.aspx

http://autorepair.about.com/library/weekly/aa031905a.htm