Having just recently bought a 2005 Ram 1500 w/Hemi, I do not have much experience with the Hemi chips or modules, however I do have about 4000 miles worth with my 2007 Mustang base model, w/ V6 & a 5 spd. I bought it w/ 33000 miles, last Sept. After installing a stainless steel 2 1/2" dual exhaust w/ stock GT mufflers, a cold air intake, my MPG went from the advertised 24 to26MPG. My next choice was a ' Jet ' Programmer & Code Reader unit. THIS was the single most dramatically satisfying move I did ! The unit takes approx 10 min's to download & save the stock prgm, upload a new one & you are on your way. It allows for an input of modifications, or stock configurations, but ALL programs are based to the fuel grade you're willing to pay for ! In other words; ' IF ' you want to go race, dial in for Premium ( It's worth it, even once ! ). I don't have HP #'s, but my intial input was to run a prgm for REG but after 1/2 tank, I filled w/ MID-Grade. This was the most responsive & economical result. I ran a 3000 mile trip to CA & back to MT & got 5 tankfuls in a row at 31MPG ! My ' JET ' programmer was about $ 325 & it's been a blast. I don't recommend a module because you can't download to ' stock ' rightaway if you need to get your vehicle serviced at the dealer, or elsewhere, since they need the stock program to do a correct diagnosis to work with. The Jet allows a download as the stock program is saved. Only drawback is that that particular programmer unit is dedicated to the vehicle that you've downloaded the stock program to. I would say to try it, I saved a lot of cash on gas on my trip, & still having fun with watching for the next performance improvement. This also was a gas, in this little V6, the surge in power thru the gears is exhilirating, before, it was a fairly ho'hum excercise in ' rowing the boat ' & felt like any other small econo-box out there. At least now, it has some ' zipp ' to it & feels like a ' sportscar ' should. Present MPG has settled at about 25-26 in combination driving here in MT. I plan to do almost the same mods to my Ram Hemi, but a dual outlet exhaust is not really needed provided a hi-flow single outlet muffler is available. I got my Jet thru Summit, delivery was quick. I am very satisfied.