I understand the principles behind the two ideas - flashing and piggybacks - but what I want to know is about fuel mileage with the two.

I've heard a lot of folks say with their piggybacks they generally increase their fuel mileage because the computers generally only change the a/f ratios in the upper RPM range.

I'm wondering if a flash is able to do this also? Since the flash is a permanent type thing without it's own intelligence, are the maps generally set to lean out lower RPMs and higher RPMs therefore increasing fuel mileage all around, or just higher rpms or does it actually cause fuel mileage to go DOWN for some reason (referring to someone who posted earlier this morning who could "barely get 200 miles to a tank of gas" after his reflash)?

I'm not the most technically knowledgable person when it comes to this stuff, but I'm learning, and appreciate any help I can get from those with the knowledge!!

 

You definitely seem confused. The reflashes are leaning out the fuel some and that will directly cause better gas mileage.
If anything causes mpg to drop it is your foot.

 

He's prolly referring to me. Let me say that the best milage I got before any mods and driving conservatively was 250 on a tank (93 octane). I used to average around 200 on 94 octane stock. I'm not sure if the higher octane is burning faster or what but thats what I averaged.

Now with the reflash and making around 310whp I've gone 62 miles and I have alittle less than 3/4 a tank left. I'm driving conservatively now to gauge my gas milage. I'll get back to you when I'm at 1/4 left.

BTW I gauge my fuel comsuption when I get down to a 1/4 tank (or alittle less) cause I don't like dropping below that.

 

So if you have run 62 miles on 1/4 tank.....you ae getting almost exactly the same mpg's as you did before the flash.