In today's letter: Does using your car's radio burn extra gas?

Dear Car Talk

Dear Car Talk | Jul 01, 2006

Dear Tom and Ray:

My husband says using the radio in the car uses gas. Is this true, and could you explain how? -- Robyn

RAY: Technically, your husband is right, Robyn. But the amount of gas is so miniscule that it would be difficult to even measure it.

TOM: Yeah. The radio might use up an extra gallon of gas if you were driving to, say, the moon and back.

RAY: The reason it uses gas is because when the engine runs, it, in turn, runs the alternator. The alternator generates electricity to run the car's electrical components -- like the starter, the lights, the air conditioner and the vibrating butt massager.

TOM: Theoretically, each of the car's electrical components makes the alternator work a little harder, which makes the engine work a little harder, which uses more gasoline. Some of this is measurable. For instance, the air conditioner really does cut into your mileage, because it draws a lot of current. But other stuff, like the dome light, the left blinker and the radio, draws so little current that it hardly matters.

RAY: So, if your husband is trying to tell you not to listen to the radio in order to save gas, tell him to flake off. Tell him that you'll save more gas if he stops talking, because the added wind resistance created by his breath is going to affect the mileage as much as the radio is.

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