While neither the horsepower nor the torque levels showed an immense increase, we'll take every bit we can get, especially considering that we have more than a few power-stealing components in place. The 245/75R16 Goodyear Wrangler MT/R tires installed on this Liberty are the same used on the Jeep Wrangler Rubicon and weigh about 50 pounds each. Compare this to the stock Liberty offerings of the 215/75R16 Goodyear Wrangler ST (26 pounds) and 235/70R16 Goodyear Wrangler SR-A (32 pounds), and we're pushing nearly 100 pounds of extra weight. The engine power is also spinning through a Klune-V unit, which also sucks up some of the extra horsepower and torque that is channeled to the rear wheels.
Despite the meager power improvements, the installation of the aFe and MagnaFlow systems still delivered some good. After running through three tanks of gas, we've experienced a significant improvement in fuel mileage. Where we were previously accustomed to achieving 10 to 11 mpg, we are now getting 12.5 mpg - more than a 2-mpg increase. The aFe and MagnaFlow systems also provided a sufficient degree of more "seat-of-your-pants" power gain, which might have been even greater with the stock-size tires still in place.
With the stock airbox removed, Chris installed the new aFe metal filter housing in its place. The housing is secured to factory mounting locations, so no drilling is required. | 
Chris then secured the new air tube to the throttle body using the provided flexible coupler and hose clamps. | 
Horsepower Results |
Torque Results | 
aFe provides an ample amount of edge trim to line the air tube hole in the metal housing, as well as for the top edge of the housing to create a good seal to the hood interior. The trim will help cut down on the amount of hot air and/or dust that enters the intake. | 
The pre-oiled aFe filter was then installed using the provided hose clamp. A prefilter was also included with the kit and is shown in place on the filter. |
Installation of the aFe Magnum Force intake system was then complete. The air tube and filter housing are good fits in the engine compartment, and we'll enjoy having the ability to clean the aFe filter rather than having to buy a replacement at each service interval or after dusty trail rides. | 
The stock muffler and tailpipe will be removed to make way for the new MagnaFlow exhaust system. Also visible is the NP231 transfer case and Klune-V gearing combo, as well as the custom J.E. Reel driveshafts. | 
The MagnaFlow kit retains use of the stock catalytic converter. Here, Chris secures the new muffler to the converter. |
The MagnaFlow muffler was then attached to the new tailpipe using the provided U-clamp. The tailpipe features two hangers that sit in factory positions so that the stock rubber isolators can be used. | 
The rear tailpipe hanger is shown supporting the slashed and rolled 3.5-inch polished stainless steel exhaust tip. The tip is a bit larger than the stock tailpipe, which required that we trim the rear bumper slightly for extra clearance. | 
Installation of the new MagnaFlow exhaust system was then complete. The entire effort required only about 30 to 40 minutes of labor and was an easy fit to the Liberty's factory components. |