There is a night & day difference on turbo engines if you are willing to run 91 or 93 octane. You have two choices. A tuner that reflashes your computer module or a piggyback tuner like JMS BoostMax. It intercepts the factory signal and changes it to provide more boost. Both have pro's and cons. The Boostmax only does turbo boost and pedal effort with another chip. A tuner you can boost, pedal effort, transmission shifts, OD lockup for better MPG, turn cooling fans on sooner and much more. The downside to a tuner is that if you blow headgaskets because of overboost, the dealer will see that the computer has been reflashed and could void your warranty. The JMS Boostmax leaves no digital footprint of any kind. You just have to remove the module before you bring it to the dealer. I use the Boostmax. The power increase is incredible and I average about 19MPG if I am not driving her hard.