I would like to buy a box, only for possible mpg gain, for my 99. I see a few listed in the TDR classifieds, and on Ebay. So I would like opinions from those of you that are in the know. What do I need to be aware of when buying used? Which box (chip) usually might a guy get an economy boost from? Superchip, Edge ,Quadzilla, etc. etc. With todays fuel prices, even a 1. 5 to 2 mpg is worth pursuing, in my book. I thank you for any replies 
