Does this steal MPG?
 

Ok so it is very obvious that the a/c is always talked about as stealing MPG. But what about these other things? And how much? Remember to be as specific as possible because if you say "it hurts a little" that could mean to me 0.001 MPG difference or 0.5 MPG difference...
1) The Heater (Does low or high make a difference?)
2) The Defrost (I think I heard it does steal some MPG)
3) Small things in the power outlet (like a GPS or L.E.D. or something)
4) Big things in the power outlet (like a 100 or 200 Watt converter thingy)
5) The Radio (Does low or high volume make a difference?)
6) Electricity of running the wind shield wipers
And don't side track and try telling me about how dangerous it would be to go without the wind shield wipers or something because that is obvious and I wouldn't anyways. I figured these things might use up MPG from running the alternator harder or something?

Obviously they all steal mpg: the power for them has to come from somewhere, and that somewhere is the gasoline being burned in the engine.

The exception might be heater & defroster. They use waste heat that'd otherwise go to the radiator. It's the fans that use power: with proper intake/vent arrangement, without fans running they might even help mpg a tiny fraction.

Yep, power is power. :)

Maybe I am misinformed but I thought the alternator was always running and always had the same resistance, so why would it be more efficient to use less electronics when the alternator is constantly recharging the battery regardless of the consumption. If anyone could clear this up for me it would be great.

Alternator
 

This is what I thought, unless you have a huge amount of stuff going on like the huge audio systems in peoples cars where they have to get a better alternator like replacing your 94 amp alternator with a 105 or 140amp...

If the vehicle is equipped with A/C... Selecting defrost for the front windshield will turn on the A/C compressor regardless of where the temperature is set. My understanding is that the A/C will "dry" the air better therefore clearing your windshield faster.

defroster as is stated turns on the compressor in most cars.

No the alt produces only as much power as is loaded.

This is how power plants function. IF there is not enough load the turbines start to freewheel (the start turning faster) and then they reduce the amount of heat they are applying to avoid wasting coal.

If you are not running anything of your alternator(your engine is being run from batteries) the alternator is not providing any substantial resistance. Go find an electric motor of any size. turn the drive shaft without the two lead wires being connected to anything. Now turn the wires connected to something that uses electricity(thats not plugged to anything else) and turn it. Its alot harder. If the electricity flow is not being drained out of the lines the EMF resistance doesn't happen.

Think about an anenometer(wind vain). If the vain is moving slower than the wind it obviously drains the wind(if it is pumping water or something), but if you disconnect it from the pump it will spin the same speed(theoretically) as the wind and not cause any(much) resistance. Alt works the same way just consider electricity a fluid and the electrical wiring are pipes and the alt is a pump, if its already moving as fast as the pump can get it the pump doesn't require as much juice.

that said everything drains juice. Stereo systems drain however many amps they are times voltage times .013 to switch from watts to hp. That inverter roughly draws twice as much power as its rated because in converting electricity you lose alot so a 100w probably draws 125-150 and 200 250-275. fans probably run about 30 watts on loaw settings and 100w on high. Any interior LEDs use tiny amounts of power, if you mean like headlight strength LEDs they are rated in watts so it tells you quickly how much power they draw(your headlights just measure the amps times 12 volts to get watts then multiply by .013 to get hp drain.)

HypermilingNoob -

Maybe a year+ ago someone posted a list of amperage uses for different car systems. I looked for it but I can't find it.

CarloSW2

http://ecomodder.com/forum/showthrea...html#post98383 is one of them.

metrompg.com had a list of items and their associated power requirements

So in other words, The more things your running the more your alternator is having to work, the more MPG your giving up.... And basically the amount of MPG you go down are depending on the power the object consumes? I think I got it right. Now how about the heater? It uses electricity obvious but is it a large amount?