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Audio & Gas Mileage


cMack

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Its not the cranking and pounding of the amp and its affects on the alternator that would hurt gas mileage, but rather the weight of all the audio gear that your carrying... that would have an effect more than the system operating...

bingo

the car is constantly charging the batteire and the altenator is running regardless if it need to or not since its on the S belt the only thing that turns off is AC and that is due to the clutch

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I routinely have my 900W system cranked in my S40 - This may be a stupid question but does this have a noticeable effect on gas mileage?

I agree with everyone else for the most part, but you guys are forgetting the LFF (lead foot factor).

See the formula below.

kicking system + high volume + killer song = 1/2 of your normal MPG

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Its not the cranking and pounding of the amp and its affects on the alternator that would hurt gas mileage, but rather the weight of all the audio gear that your carrying... that would have an effect more than the system operating...

Depends whether we're talking about city or highway driving. You'd only "pay for" the extra weight when accelerating, and if your system weighed 150lbs on a 3500 lb car that's like 4% more weight? One could probably set up a system for 1/2 that if they focused on weight reduction. If you're on the highway you're only countering wind resistance so it wouldn't matter how heavy it was.

bingo

the car is constantly charging the batteire and the altenator is running regardless if it need to or not since its on the S belt the only thing that turns off is AC and that is due to the clutch

Kinda. As the load on the alternator increases, the voltage regulator increases the current going to the field coil, which creates additional torque on the shaft and thus consumes more mechanical power. Sometimes the belt will squeak over the alternator pulley if a large load kicks on real fast and the belt is loose. However, we have 100A alternators, which is ~1.2 KW (100*12) which is 1.6 Horsepower when converted directly. Alternators aren't terribly efficient, but even if we double that it's still only 3.2 Horsepower. You still have to power headlights, ECU, etc, so you'll never hit zero, but the load could still go up by say 2HP if you crank it. I think it takes 20-40HP to keep a car rolling at highway speeds on level ground, and if that's correct, that's a 5-10% increase in work being done. How that translates into fuel consumption with engine efficiency I have no clue. You'd never notice that in the city, though. All the same, I always turn off my headlights, stereo, AC fan, and everything else that draws power when I'm at the track.

I agree with everyone else for the most part, but you guys are forgetting the LFF (lead foot factor).

See the formula below.

kicking system + high volume + killer song = 1/2 of your normal MPG

LOL.

I'll agree with this 110%. I know if I switch from classic rock to techno or something with a fast beat I lose 4 MPG highway and 8 MPG city. :D

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  • 2 weeks later...

In the lame town of melbourne florida when you have you system bangin you are usually driving real slow trying to pic up some hoes therefore I get increased gas mileage.

hahahahaha there are no hoes in melbourne buddy. and if thats your plan sell your volvo and make us all look better.

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