Stereo and MPGs?

[steve_spackman]

I haeard a rumour that having your stereo on can affect your mpgs...

Is this true or false?

[airshifter]

In theory any electrical load can affect MPG. In reality you'd have to be running some massive power to have a stereo system affect MPG in a way big enough to measure. The weight of the system would probably have more impact in most smaller cars.

Unless of course you are driving faster because you like your music!

[Jag_Warrior]

Are we talking about a car with an internal combustion engine or some sort of hybrid or electric car? If it's not one of these new George Jetson moblies, the alternator is being driven by the engine whether you have all the accessories on or all the accessories off. I can't see that it would matter.

[Dave B]

A typical factory fitted unit, on full volume, would draw about the same as one headlight bulb. A huge ICE system would obviously use more, plus the mass of any speaker enclosures.