I am thinking about doing some mods to my truck. I'm thinking about getting jba headers, x-cal tuner, cold air intake, and underdrive pulley. I have a 4.0 4x4 auto and currently get ~15mpg. Only mod I currently have is a cat-back system. Anyone care to guess how much hp and mpg I could gain from these mods?

 

I have a 3.0 with 31s and 4.10s and get about 17hwy/city with a x-cal. I'd say your best money would be on the underdrive pulley and driving accordingly. Tuner i don't think netted me much gain, i'm going to go back to the 89 tune from the 87 and see if it gets me anywhere.

 

If your milage doesn't drop 1-2, I'll be very surprised. I did the same thing (dropped to an 87 tune), and milage went to 14!!! I am at about 16 now.


I want to do UDP's and ignition coil pack...then it's on to bigger and better things.

 

has anyone done dyno tests on these mods? I'm really curious to see the gains.

 

The best way to increase your MPG is by changing your driving habits! Don't throw your money away on useless performance mods!!

 

underdrive crank pulley pulled another 7-8?rwhp and 11rwtq i believe. Those are just figures off the top of my head. I'd like to pick one up for my truck. I can use a new serpentine belt on my engine, but i'd like to wait until i can get the pulley as well.

 

well I'm not doing this just for the mpg, I want more hp. So, if you can answer my above questions please reply, if not move along.

 

x2, I had one for a LONG time, and gave it to dominic (a member on here) and I did notice a power loss. I took it off because i couldn't get rid of the belt whine (even after a new belt), narrowed it down to the pully, it was worn down. But dom has no probs with it that I know of.

I'm looking for another one soon. It's up there.