Originally Posted by snrusnak
Dyno's are proof enough for me. I've seen customers dyno their cars after buying the product and their results matched the advertised numbers, so I don't think they are bogus claims. Keep in mind, these are performance tunes running A LOT of timing advance. You can't tow with these tunes, or you'll end up with detonation. Also it is with higher octane fuel to resist detonation with more timing advance. This is why the factory can't tune them this way, they have to be tuned to suite all applications.
I'm guessing the big gains with the 4.7 are due to adding a lot of ignition advance at low/mid rpm. I'm about to buy the superchips for my 2010 and use the 87 octane tune. Im hoping it's not too much ign advance when I'm towing my enclosed trailer. I may have to use 91 octane.