+1 on the procal! then you can also download the gas cubby app on you iPhone for another type of reading (more accurate)

 

A Procal is nice if you want to get your vehicle back to having a calibrated speedo, while a programmer will increase performance and efficiency.

 

Another way to help..... Don't drove 80 on the highway. I have been driving a lot slower and my MPG has gone up, sounds like common sense but its true.

 

If you only want a couple more mpg then all you have to do is get rid of the slush box! just kidding get calibrated and i'm sure you will find you are doing better than 10mpg.

 

Stock rubi here, I found that I was getting about 10mpg and was like wtf. I then did some thinking and realized every morning I let it run for about 10-12 minutes before I take off. My true mileage is around 17-18 while driving, having it idle brings it down to 10. I still think that seems a little odd that idle gas usage is that much but whatever.

 

My Jeep has 4 speed auto, 3.73s, 2.5" lift, 35s, Body Armor Rack, and a Body Armor rear bumper.....I get 12.2 city...13.3 highway I have the AEV Procal and just like Jpop said it will only correct your speedo and thats what it did! I need to get the SUPERCHIPS tuner I have heard only good things about it.

 

Best ways to get more mpgs is Procal/Tuner and regear.

I was getting 10 mpgs before I regeared and recal'd with the Procal and now I get 14.5 around town and 16-17 hwy on my 35" KM2's

 

It's ok I am getting
12mpg with a 1.25inch lift and rubicon take offs

 

With summer gas and superchips with my 33s stick shift and 3.21s I get 19 to 20 mpg. I shift at 2500 for first to second and at 2000 for the rest.

 

i get 17 mpg, im running 513 gears 35 inch km2 tires, i did throttle body spacer, k&n intake and repo the computer for the tires and gears.