I upgraded the stereo in my car... how will affect MPG?

[born2drv]

high powered mid/tweeter combo... 1 high powered sub ... about 250watts at full output... I probably have it 1/2 way cranked most of the time on average so lets say 125watts drained while driving the car.

What is the net effect on MPG in your opinion? I seem to have had about a 3-4MPG drop, is that about right? When the car is off and the stereo is at full blast (250watts), it consumes about 1 bar on the battery gauge every 5-7mins.

Anyone put a stereo in that was so big it sucks the battery dry in a matter of minutes?

[Corey872]

Yep, back when I was young and stupid, I had a nice stereo with a big amp to blast the tunes...now that I am older and have tinnitus (constant "ringing" of the ears) I have started to choose quality over quantity.

As for your amp, 1 horsepower = 745 watts so even blasting full volume for hours shouldn't have a huge impact on MPG.

[coolcat]

Your stereo shouldn't affect your MPG at all, not a single bit. I have a very large and powerful stereo and it has absolutely no effect on my mileage.

[Yves M.]

Hi,

Are you writting about 125-250 watts of sound or of electricity. They are not the same. You need more that 250 watts of electricity to create 250 of sound. Basiccaly, amp, display, tranfo losses, .. will add up. You need to check the current draw to know of much energy you are using.
But that energy will come out of your gas.

From memory (and that is really vague), I think that it takes about 2500 watts of electricity to have an amp blow out about 250 watt rms on two channels (left-right) of sound with good bass. Again, Only an approximation.
[edit] 2500 is not possible, would make for too many amps in 12v. So it is lower than that

Hi Born2drv:

___I will probably never be able to calculate nor ever hear someone give an actual mpg loss figure for a given Stereo and Amp setup running a normal volume level but there will be a loss. I try and run my accessories including the radio as little or as low volume as possible knowing that even a hidden charging of the 12 V from the IMA’s MG set through the converter is a loss of fuel economy no matter how small. I actually have a portable CD/MP3 player running off AA’s for CD’s when I am in the mood. I do however run my PDA based GPS off the accessory outlet on an almost continuous basis and listen to “Book’s on Tape” for most of my hours in the Insight. Running the cassette player is probably a small drag on the system as well? We all have our minimum luxuries and or comforts in terms of what we will and will not stand for, right

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:1oq5ds3a]Waynegerdes@earthlink.net[/email:1oq5ds3a]

[windmill]

Originally Posted by coolcat

Your stereo shouldn't affect your MPG at all, not a single bit. I have a very large and powerful stereo and it has absolutely no effect on my mileage.

It will always cost something, you use energy, if you use let's say 750 watts, it has to come from somewhere. If you use energy you have to create energy. I know that 750 watts isn't much and you won't see it much in your fuelburn, but I think it will cost something
Maybe a few %.

[coolcat]

Originally Posted by windmill

It will always cost something, you use energy, if you use let's say 750 watts, it has to come from somewhere. If you use energy you have to create energy. I know that 750 watts isn't much and you won't see it much in your fuelburn, but I think it will cost something
Maybe a few %.

Ok, if we're going to nitpick, yes a stereo does use energy and yes that energy does come ultimately from the gas tank. However, the biggest impact that a stereo system will have relating to MPG will be in terms of its weight (increased mass of the car). What I'm saying is that in the real world not only will a large stereo not impact MPG through the electrical system (mine never has, and I'm pushing about 700W of real power through it), but its weight is also negligible (even my ~200 lb. system didn't hurt my mileage). Any MPG hit you'll see from a stereo will likely be so small as to not be measurable.

[Ecfool]

Ok I have 2 amps a 500w for subs and a 600w for the 4 door/ kick panel speakers with tweeters. At half volume I only pull approxiamtely 20 amps off the 12 volt system, so no the amp draw is minimul as far as MPG. The real killer is if you run heavy subs (approimately 100lbs and an auxillary battery to power system) then you will take a slight hit in mileage but even that wasnt drastic. This was confirmed when I participated in a mileage comparison run with Willy and his red rocket once (the results are posted here if you look back on the older posts) so enjoy the music and dahmm the mileage loss!!!!

[Yves M.]

I second that!