JohnnyQuik

If there was cheap horsepower or extra mileage to be found by using a different air filter design, don't you think Chrysler would have done so? If you could really gain 5 or 6 mpg with a "cold air intake", don't you think Jeep would change the design tomorrow. That would be the ROI example in the history of automotive design. Same thing with exhaust or engine tuners. There's no cheap horsepower to be found without sacrificing something. Normally it's reliability.

imacb278

Airaid CAI and Magnaflo muffler gained me 2 MPG on my 08 JKU. It was a manual with 3.73 gears. I don't really care what people say about the mods, if the manufacturer could do it they would. Free flow exhaust come with there quirks, mostly they're louder, CAI's are open air filters that require more maintenance and are prone to hydrolock if you're not careful. So, naysayers who like to say if the manufacturer would do it they would. Just remember they're building for the masses and for practicality.

JPop

Designing automobiles is an arduous process. Cost is always a huge part of the decision making process. Marketing people have their say as well, with price point initiatives, efficiency concerns and mass market appeal. Things like intakes and exhausts can build nominal efficiency (certainly not 5 or 6 mpg) but they make more noise, use more expensive components and at the end of the day don't sell more vehicles. A smaller muffler would dissipate less heat, keep exhaust velocity up and it's a huge can simply to keep down cabin volume. Automatic transmissions have efficiency robbing shift softness to give the passenger a sense of smoothness. There is simply a ton of stuff that isn't done and not at the behest of engineers.

atomthompson

I love it when people call me (or others) liars on here. I did have a 5-6 mpg gain, which I completely agree is not normal. However I have a 2,883.0 mile drive (with 500 pounds of cargo) and all of the recorded mileage/gas purchases to back it up. So yes it is possible to see significant gains, just as it's possible you won't see any. I didn't get anything out of my exhaust or tuner yet I don't go around claiming anyone who says otherwise is wrong.

As far as the manufacturers doing it if they could, cost and time is a factor. They put out the product with the least expensive items that they can use to make the quality level that they want. It keeps their cost down and their profit up. Then the aftermarket side gets to come in and spend several months/years designing one or two specific designs for that vehicle and can charge several hundred for it. Afterall a quick look on here will find people with bent C's on their d30 and d44 axels and yet the JK doesn't come with so much as cheap gussets welded on from the factory. If the OEM was perfected the first time out there wouldn't be aftermarket anything, let alone thousands of options.

Getting back to the original post. I would still recommend some of the modifications that have been mentioned on here. Intake, exhaust, tuner (once their crack the encryption on 2011+), turbo/supercharger, and/or gears. Other than that you are unfortunately stuck with a slow mover. But who cares if a toyota yaris beats you off the line, you'll fly past it while it's slowing down for speed bumps and every dip in the road.

armycop

Right now, the only things that work on the 2011 are the Sprint Booster and the Procal. The Sprint Booster gets rid of the electronic throttle lag, and the Procal helps the Jeep recognize tire size and adjusts the shift points closer to stock. Neither one increases power, but may give the Jeep a little more quickness off the line.

DR-WRANGLER

Headers are not suggested from what i see..

JohnnyQuik

Manufacturers design vehicles to maximize profits. There is no way that they would not change the design of a component to yield a 10% to 20% improvement in gas mileage or horsepower for a negligible increase in cost. The major issues with "cold air intakes" is that they typically suck in hot under hood air into an open filter element that doesn't filter as well as a stock paper filter. Google K&N dirt in intake. Unless there is a compressor to force more air into the intake manifold, it operates under a vacuum. Assuming you don't have a dirty air filter, even completely removing it won't yield you anything much without other modifications.

JPop

My efficiency increases from an in intake and exhaust came in at under 5%. With it I had more cabin noise, more under hood noise and an intake more vulnerable to taking on water. The EPA testing for efficiency probably doesn't net enough of a difference with the highway speeds they test at of 60mph and under to net a yield high enough to bump the ratings on the window sticker and if they did probably by just a single mpg.

Let's say Chrysler did manage to get a bump of a single mile per gallon increase by changing the components mentioned. How much more did it cost? How many people turned away because of the increased cabin sound levels? How many more engines did they need to replace or repair?

There are lots of things that can be done to modestly increase fuel efficiency and power. Chrysler needs to determine the cost/value of them as they are perceived by the overall market. After market parts are certainly overstated by their manufacturers, not that all of them are snake oil, just your results probably won't match theirs born under a third moon. For the upgrades I made to my JK it's unlikely I will ever see a return on investment, despite having better efficiency and power. Had I gone some different directions, I'm sure I could have, but the vehicle that would have been placed on Chrysler's lot wouldn't increase sales enough to justify the cost and assuredly would turn some customers away.

Bosox5

Gears, or go with a 2012. 5.13s have been awesome with my 35s and the auto..much more low end power.


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CSIERRA

thanks again everybody for your help I really appreciate it !