Note: I installed this back in late 2011 when my Rubicon was completely stock.
Bought this for highway drivability and towing power. Before the RIPP SC, I was afraid to take the interstates because I simply couldn't accelerate fast enough to merge with traffic. It was worse if I was towing my open 6x10 trailer.
Installation was straight forward using tools the average home owner has in the garage. Screw driver, socket wrench, scissors. No welding. Hardest part was removing the intake plenum...one screw near the firewall is difficult to reach. Takes 6-8 hours to install. Everything you need is included to make it "plug & play". New spark plugs, fuel injectors, all the hardware, etc. The instructions are very detailed, and there is a video on YouTube that shows everything.
After installation, it fired right up. No check engine light. Once on the road, the difference was incredible! Added over 100 HP, and about 90 ft-lbs of torque. Now I can easily cruise down the highway, even while towing a fully loaded trailer. Acceleration is crazy compared to stock! Maintenance...just change the supercharger fluid every 8,000 miles, piece of cake.
The advantage to this supercharger (centrifugal) over the roots-style blowers (i.e. Sprintex / Magnuson) is the power comes on more gradually. You don't have a ton of torque dumped into the drivetrain at idle...which is what breaks things. If you want additional torque...that's what 4LO and axle gearing is for.
And yes, the MPG does increase 2-3 mpg, IF
you can keep your foot out of the skinny pedal and drive like a normal person. LOL!
If you want highway drivability, this is the ticket. The best power/$$ modification you can install. Much cheaper and less complicated than a V-8 swap. Also CARB compliant for those in emissions-tested areas. Best mod I've done to my JK!!