Fuel economy lost from amps \ sub enclosure weight?

Just curious if anyone noticed a significant change in fuel economy from the extra weight in the trunk. I've been trying to isolate why mine isn't that great and I don't remember it changing much when I added the box & amp but I wasn't really paying attention to it much back then.

I'm averaging around 12L/100km or 19MPG with mostly city driving in a 325Ci.

For city driving on a 2.5 motor, I say that's rather low - I get about 21mpg city on a 3.46 diff!

..and I don't understand why people add a box, sometimes dual, in that little trunk? In addition to lowering your hp/weight ratio, the bass doesn't sound half as good as an IB set-up, which I have!

That said, as a start, change your plugs if they have never been touched and your tires too if they are a little aged.

it shouldnt make much of a difference, its not like ur adding 300lbs. 50lbs or so isnt gonna change much

Originally Posted by Many330i

For city driving on a 2.5 motor, I say that's rather low - I get about 21mpg city on a 3.46 diff!

..and I don't understand why people add a box, sometimes dual, in that little trunk? In addition to lowering your hp/weight ratio, the bass doesn't sound half as good as an IB set-up, which I have!

That said, as a start, change your plugs if they have never been touched and your tires too if they are a little aged.

I beg to differ. I just had a 12'' put in the trunk in a built sealed enclosure and I'm pretty sure that it would beat down any free air set up in the same ballpark of audio parts used. That, along with 2 amps and a set of components, probably added a total weight of 25lbs to the car.