Modules are available in two configurations: Stage 1 and Stage 2.
The Stage 1 Module is recommended for stock or mildly modified vehicles. Programming is designed to burn fuel at peak efficiency, increasing mileage while using regular fuel (for performance gains the use of mid-grade or better fuel is recommended).
The Stage 2 Module is recommended when the end goal is increased performance. It features more aggressive programming to make the most horsepower and torque available. Fuel and timing curves are extensively modified for peak performance. Requires use of 91 octane fuel, 180 degree thermostat and free flow exhaust. Also works well with aftermarket intake systems, mass air sensors, TBI spacers, etc.
You can go to the JET's website for FAQs regarding performance, suitability, environmental compliance, etc. In this page you will find the model numbers for the Stage 1 and Stage 2 modules that fit the Jeep Commander's three engines: 3.7L V6, 4.7L V8 and 5.7L V8. And, if you go to this page you will find a write up and pictures by a guy who actually installed and tested one of these modules in his Dodge truck's 4.7L V8.
While so far I haven't been able to find any Jeep Commander owner actually using the modules, there are a couple of Jeep Grand Cherokee owners (4.7L and 5.7L Hemi) in JET's Testimonial Page that apparently are very satisfied with the results. If you are a Jeep Commander owner who has tried the modules, please feel free to add your comments.
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