Originally Posted by gonefishin776
Well I put on the 87 octane tune and saw a small decrease in mpg. But I installed the tune specially programmed for mileage then drove conservatively and that's where I saw the MPG gain. So yea, the performance tunes will most likely result in a drop in mpg if anything. I'm just pointing out that with the correct driving habits the mileage tune did help me.
Try a test with the highest performance tune and I bet you have the best mpg ever. I have tried numerous tests on different vehicles, all Dodge and the absolute best performance and mpg came from the 91 or 93 tunes.