K&N Cold Air Intake Kit: High Performance, Guaranteed to Increase Horsepower: 2011-2019 Jeep/Dodge (Grand Cherokee, Durango) 5.7L V8,63-1563

Put this on wife's 2014 Durango R/T with the 5.7 Hemi. It has a noticeable power increase on regular around town acceleration. You don't have to use the accelerator as much to get to your normal driving speeds. I think that is where you will receive a MPG gain, if any. The good whoosh sound noise doesn't really come in 'til you dig deeper on the accelerator and then it sounds terrific. Makes my kid laugh in the back seat every time. I wouldn't recommend buying it if you are just looking for MPG gain because it is probably not significant enough to pay for itself. I would recommend buying it for the improved throttle feel and the great sound it makes when you drop the hammer.

I received the Performance Intake Kit for Christmas (This is the only thing I asked for from my wife) and promptly installed it with no problems. Its very easy to install, I think it only took me 30 minutes from opening the box to clean up. I installed it on my 2011 Jeep Grand Cherokee with the 5.7L Hemi. The sound is almost the same as stock under 3000 RPM, so cruising speed and normal acceleration is not noticeable. Once over 3500 RPM however, the roar is very satisfying. It sounds like a muscle car and not a SUV. I've done some freeway driving since installing it and have noticed a slight increase in mpg but it's offset by the fun I'm having listening to the engine while accelerating (I even turn off the radio when getting onto the freeway on-ramp). Best Christmas present ever!