We used to be especially skeptical about gas engine tuners. Thankfully, newer gas-powered autos can finally get legitimate results out of the handheld programmers. The Banks Automind Programmer gave our ’04 LJ four pre-programmed settings. We’ve cycled through each and found the most noticeable by far is the Super Sport 91. Obviously, this requires a higher octane (93 is actually available where we are on the East Coast, but 91 was the only option). After a few tanks on the high-octane setting, we dialed it back to Sport 87. Ultimately, the performance gains were not enough in the higher settings to warrant the higher price of fuel. It takes only a few minutes to cycle through tunes, so we can quickly swap between.