Quote:
Originally Posted by jedi_sol
if CA98civic doesnt mind me answering for him  |
hahaha! Yeah, that's fine.
Quote:
Originally Posted by jedi_sol
It doesn't make any difference in mpg if his battery is draining faster than normal.
it's cuz he is running with no alternator, therefore, battery drain is extremely important to track. You simply just dont want to be stuck in a parking lot or on the side of the road because your battery has no more juice 
am i right, CA98civic? |
I run without the alt, generally, though I do turn it on for braking assist sometimes. I also run it whenever the battery voltage under load drops close to 12.1 or 12.2 (to preserve longterm battery life). The switch is an awesome benefit for this. This means, of course, that a lot of fan use will reduce the battery level and force me to run the alt sooner than I might have, thususing more fuel.
Quote:
Originally Posted by johnlvs2run
To rephrase, as I'm having a similar issue with the fan, how much difference could this be making with my mpg?
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I wish I knew for sure. Assume you're losing maybe 1 HP to a running electric fan, which has to get its power from the battery, which means ultimately the alternator and gasoline. The HP loss might be less. If it takes about 10 HP to propel a little Civic like ours along the freeway, 1 HP is about 10%. Looked at differently, MetroMPG ran a test and posted the results here in which he happened to see a 10% fuel economy difference with and without an alt. Our Civics are different we have OEM electric load detectors that help the ECU control alternator output according to charging needs and driving conditions. Our cars sometimes shut the alt off by design. That said, I thought I saw a 3-5% difference when I was experimenting, but I did no ABA testing.
In short, I don't know how many MPG it costs, but I prefer to keep the fan off as much as if safely possible.
Does anyone know how much power the fan actually draws? 100 watts, 50 watts?