ok i've heard from several people that an underdrive pully will create a noticible difference in fuelmileage and will give you a slight horsepower boost. well heres my question sence my truck has an aftermarket sterio system and it uses a lot of power to run my amp and subs would that cause any problems with my battery charging having everything spinning slower? because my sterio already makes my headlights dim and the gauge move over about the width of the needle every time the bass hits it stays pretty much on 14 amps on the gauge so will this cause me problems installing this? thanx in advance

 

yes, it will. You need to get a capacitor inline with your sub amp anyway, but going to an underdrive pulley will only compound the problem, and you could start burning out your alternator (if you aren't already).

 

What is a good underdrive pull set?

 

the more power your stereo uses the more load it puts on the alternator. The more load the harder it is for the alternator to spin causing it to rob more HP from your truck. Obviously you need another CAP or 2. Or a bigger alternator, that way it wont be so hard to turn.

 

OK so what would i have to do to be able to run the underdrive pulley without tearing the crap outa my altinator and ending up with a dead battery? and i do mean besides turning my radio down cause thats out of the question lol but do they make something to where the underdrive pulley would spin everything slower but still spin the altinator fast? like something that goes on the front of it that acts in the opposite way of the underdrive pulley system? fuel just jumped from 2.60 to 2.98 at the gas station here today so i really wanna try to squeeze some miles out of my truck

 

yea you can buy a pulley set that comes with 3 pulleys to counter that

http://www.autotrucktoys.com/dodge_d...8358C2118.aspx

and fuel here in manteca CA has been well over 3 bucks a gallon for several months