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Do Cold Air Intakes Improve Fuel Economy?

30K views 27 replies 18 participants last post by  moparado 
#1 ·
I have read everything I can find on this forum regarding CAIs. I am thinking about adding a CAI to our 2012 Grand Cherokee with a V-6. I am looking to improve economy and performance sound if possible. Does anyone have any data regarding if indeed fuel economy increases due to installation of a cold air intake?
 
#3 ·
I have no data on the grand cherokee to back my statement, but IMO absolutely not. First off I have yet to see an actual "cold air intake" for the Jeep. As far as I'm concerned any intake where the filter is in the engine bay is doing nothing but suck up hot engine air even if there is a metal box around it. The OEM box is designed to bring in air from outside the vehicle. Even if a cold air intake was proven to provide measurable increased fuel economy it would likely be eliminated and worsened by slightly more aggressive driving habits. Cold air intake sound is only noticeable when you drive harder.
This is all just my opinion so take it for what it's worth. Some will disagree, but I have used CAI's on cars before and never noticed improved economy as far as I can remember.
 
#4 ·
Not long term, you certainly won't save enough fuel to cover the cost of the CAI. The benefits of a CAI are style and sound. To take advantage of CAI potential, you need to retune the engine, which is probably tuned to max mpg anyway.
 
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#5 ·
I just recently installed a CAI on my car. I'm from Canada so I'm not sure what my MPG is but my car used to be around 15-16L/100km now with the intake installed I'm getting 13-14L/100km so IMO it's worth it for the fuel savings and the improvement in performance. Can't get enough of the way it sounds to.
 
#7 · (Edited)
I was looking at the design of how the stock airbox draws cold air, and it seems like disabling a system that is actually drawing cold air from outside the engine compartment would be counterproductive.

Would a stock replacement K&N or a (dry) aftermarket air filter perhaps be a better alternative to a CAI?

However, I sure like the look of the Mopar CAI but, if I can look forward to worse economy with it, buying one just wouldn't make sense.
 
#26 ·
I was looking at the design of how the stock airbox draws cold air, and it seems like disabling a system that is actually drawing cold air from outside the engine compartment would be counterproductive.

Would a stock replacement K&N or a (dry) aftermarket air filter perhaps be a better alternative to a CAI?

However, I sure like the look of the Mopar CAI but, if I can look forward to worse economy with it, buying one just wouldn't make sense.
I use both a K&N and an aFe direct replacement high flow filters in my 4.0's stock air box.
Both are of the washable dry type.
They both seem to empirically improve performance somewhat.
Whether its a placebo effect or a real performance improvement is next to impossible to quantify or prove without dyno testing.
Far as better fuel mileage, the 4.0 inline 6 is plain and simple a gas guzzling engine so i never cared about that.
Some people even call the venerable 4.0 a tractor engine. lol

By the way the aFe filter had a serious fitment issue when installed in the stock air box but i managed to squeeze it in after some choice 4 letter words.
The K&N fit perfect first try.
 
#12 ·
I had a CAI on my 2008 wrangler.. banks system with throttle body turbine junk.. it was all a boatload of snake oil.. =0

Made a bunch of noise.. when you mashed the gas.. reminded me of a cartoon car. (yes I get it in 2008 those mini van engines sucked.. but nothing you bolt on made it better)

No I didn't PAY for the stuff, I was at valvoline getting an oil change.. and the kid working there said his friend bought it all .. used it 3 days and said it was JUNK.. if he could bolt it on mine.. I said try it.. junk.
 
#13 ·
I bought my Volant and bolted it on a couple days after taking delivery, so I have no idea if it improves MPG over stock. Most likely it doesn't unless you can combine it with a free-flowing exhaust and engine tune. I average 17/21 now, so I'm happy w/ the MPG. I do know it opened up some space in the engine bay and the Donaldson filter w/ a 100,000 service interval is very nice. Don't buy one expecting any drastic MPG increases.
 
#14 ·
If you think about it, these car companies spend tons on R&R to find out how to perfectly match air to fuel ratio on these stock intakes. When switching to aftermarket CAI's you sometimes restrict airflow due to those companies making smaller piping and adding a filter that's open (not in a box) to engine heat a lot more then the stock.

So unless you are spending thousands on an engine setup thats included with a supercharger or turbo, its just for aesthetic purposes and for some the sound as well.

Try Swiss cheesing your stock intake box to get the same sound if that's what some people want.
 
#15 ·
I added a cheapo Ebay CAI to my 99 Cherokee with the 4.7 V-8. Yup, it sounded better when I punched it and I thought it improved my performance and mileage. That was until I was planning to trade it in on our new Grand Cherokee and put the stock airbox back on. When I did I was shocked to to see the mileage jump up roughly 1 MPG. I could hear the "whistle" sound again through the airbox that the 4.7 makes when everything is just right and achieving optimum economy. I have left the stock airbox on ever since. However, in all fairness, I believe there is a K&N replacement filter in the stock airbox. That may be helping?

Doesn't someone make a high flow after market filter for our WK2s that breathes well and does NOT let dirt through?
 
#17 ·
Sorry, but why would anyone think that screwing with the OEM equipment on their vehicle would increase fuel economy? These companies spend millions of dollars to maximize fuel economy to satisfy federal government regulations and brag about their fuel economy numbers.
For my interests, I recently added a Corsa CAI, Corsa cat back sport exhaust system, a Stage 3 Performance Chip OBDII Module, and Pedal Commander all to improve my driving experience on my 2012 JGC Laredo 5.7L 4X4 that I've owned since it was new (now with 85k miles on it). I'm very please with how it sounds and performs now. None of these mods seemed to have affected my fuel economy either way but have increased my driving pleasure greatly. The HEMI badge that I added to the lift gate does let drivers know what just passed them.
 

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#19 ·
The real answer is; yes, no, probably and maybe...

The stock air box and intake is not just there for increased engine performance. Whether that performance is power or fuel economy. It is also there for sound restrictions. Not just ever-increasing governmental restrictions, but consumers want a very quiet ride. While I personally love to hear the deep inhale of my motor, because I know what is coming next, not everybody does. The manufacturer must balance all this with vehicle styling and limited space under the hood.
 
#27 ·
I've been tuning cars for 40 years, and I've never seen a cold air intake that made a significant difference on a stock, fuel injected engine, with the possible exception of a mechanical fuel injection system, ala my BMW 2002 tii (which still requires some air/fuel mix tuning). Any gains in HP or MPG will be minuscule, if any. Alot of them sound amazing, but performance wise, I've yet to see one worth the money.
 
#28 ·
The only vehicle i installed a hi-flow filter is in my old XJ 4.0's air box and it seemed to improve performance noticeably but i'll admit it could be wishful thinking.

If the original OEM replacement type filter is of a crappy design or clogged, installing a hi-flow filter will definitely help some with performance and mpg.

Theoretically, the more air into the throttle body, the greater the fuel to air mixture which should again theoretically increase performance.
I guess it all depends on what one is starting out at.
 
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