I got like 1 mpg out of the 87 tune but having to reprogram it every time I'm loaded down bugged me so I've been running stock tune now. I mounted my flash pack in the jeep right by the a pillar and use it as a gauge cluste while I drive. I monitor temps voltage and stuff like that I think it's a good use of the system it can display 4 gauges at once and this featur makes the price worh it to me.