cbehney

Yeah and if you're chubby chasing, you really want to be able to use the A/C.

wanabe

nope, its the button that lowers the top!!!

(the top is that thing under that black plastic thing behind the seats- it is optional... and some of us have never used it- going on 8 years and i havent seen mine yet!)

Barry in Wyoming

Mr.E.G.

hmmmm. are you sure about that? i mean, you're summary is right, but are you right by accident or are you really right? lol.

the electrical system of a car produces an abundance of electricity exceeding what the car actually needs. so if the alternator rotating at 2000 rpms of engine speed is capable of supporting 100 watts of power consumption (im pulling these numbers out of my ass) and your head lights are off and the radio is off then that much power isnt being generated.

generally speaking, a power supply provides a set voltage (think 12 volt battery) and it has a peak capacity of continuous current draw that it can sustain. voltage is essentially the force (mathematically voltage is represented by the symbol E which is short for Electromotive force) behind the electricity in the system, and current is the physical number of electrons that is running through the system. current is expressed in amps. power is the product of current multiplied by voltage.

just thought i'd throw that in there so it makes sense.

so like i was saying, the alternator (works the same way with a battery or the socket on your wall) doesnt push out electricity. electricity is drawn from it. thats a minor detail that makes all of the difference in the world when it comes to understanding the system. so if the cars electrical systems are drawing only 50 amps of current and then you turn the headlights on and the radio up to full blast and suddenly the combined current draw is 100 amps then all you are really doing is drawing the current that the alternator is naturally capable of putting out. otherwise it is just spinning for no reason and its not working at its full capacity.

an interesting aside: many electric companies have what they call average billing where they bill you the same amount all year. you usually end up paying less which sounds wierd because 'why would the electric company want to make less money off of you"? well its the same thing as the alternator thing above. instead of a car engine turning the generator it's a river or steam heated by a nuclear reactor or burnt coal.

their factories have a peak efficiency for generating electricity and ideally they would like to use the same amount of coal every day, or the same amount of water flow, etc. but, consumers dont always use all of they electricity that the power plants are capable of producing so its like they are wasting the coal when people are not using as much electricity. so average billing is a way for them to encourage you to use the same amount of electricity all of the time.

so back to alternator thing, your alternator isnt exactly asked to work "harder" (semantics here) with the ac on, its effectively being asked to work nearer to its full capacity, but like G127 said, it does technically effect the alternator in the amount of current consumption that it takes to run the fan higher which would probably translate to a difference of about .00005 mpg.

sorry. i just felt like talking. lol.

G127

The greater the current draw from the alternator (i.e. higher fan speed), the greater the magnetic resistance inside the alternator and therefore the greater the mechanical resistance to turning the alternator pulley. Here's a discussion explaining it in more detail:

https://www.s2ki.com/forums/index.php?showtopic=299927

Slithr

One technique I've seen for maximizing mpg with the a/c on is to keep fan speed up, use recirculate and set the temperature down (warmer) a little to keep the compressor from running as much. The compressor will kick in and out as it is needed to maintain the set temperature.

Tyraid2K

next frame:
sideways into a tree

cbehney

I hope not, but...

Barry in Wyoming

Yes, except for Blizzak MZ-01 tires on all four corners.

The OEM SO-2 tires do not function in the winter.

SO = Summer Only

brunodkid99

simple solution for me is to turn off the a/c when i start off in first gear and through second gear. Then turn the a/c back on. glad that the button is close to the steering wheel. But yeah the loss in power sucks with a/c on.