93 Regal alternator (power) usage vs mpg

[noclues]

I have a (general) question about the 93 Regal (3800 engine).

Does it matter how much current my car electronics draw and does it impact my gas mpg?

To be more specific - i know that the alternator (100 amp i believe) is constantly turning at the same speed as the engine - and it will turn the charging on or off based on the battery level it senses.

so i would assume there is zero difference to my fuel consumption if i use a 200 watt AC converter or just a 12 volt mp3 player because the friction caused by the alternator is the same whether its charging or not.

can anyone confirm/deny this? i need to know how careful i have to be with my electronics considering $4.25+ gas prices ...

Thanks!

[HotZ28]

If you have an alternator that can produce 100 amps of current (max) and the total current demand from the electrical accessories (including the battery) is only 20 amps, the alternator will only produce the necessary current (20 amps) to maintain the target voltage (which is determined by the alternator's internal voltage regulator). Remember that the alternator monitors the electrical system's voltage. If the voltage starts to fall below the target voltage (approximately 13.8 volts depending on the alternator's design), the alternator produces more current to keep the voltage up. When the demand for current is low, the full current capacity of the alternator is not used, or produced (a 100 amp alternator does not continuously produce 100 amps unless there is a sufficient current draw). It does take a slight bit more HP to produce full alternator current, however, you would probably never notice the difference in MPG.

[noclues]

Originally Posted by HotZ28

It does take a slight bit more HP to produce full alternator current, however, you would probably never notice the difference in MPG.

ok thanks. i imagined that was the answer just wanted confirmation from the ones who have more experience with cars!