How does CAI affect fuel economy?

[Chiggles]

Just replaced the air filter in my stock airbox earlier today, and even though I've been considering getting a CAI on and off lately, the realization occurred to me that I actually don't know if a CAI would worsen my mileage or not. It's well known that CAI's improve performance SLIGHTLY, but as a trade-off, would I hurt my fuel economy a little? Mileage to me is more important than a small performace increase - that's only a bonus.

[doublepostwhore]

Nope. A CAI does NOT affect mileage, Infact it increases mileage.

[GTS Jeff]

It will improve your mileage, but only SLIGHTLY just as it only improves performance SLIGHTLY. Just driving slower will save you more gas. :)

[SilentGiant]

really?

after I put in the CAI I lost about 50-75 km per tank..

I would think that more air going in, increases the amount of fuel you burn...

[PorknBeans]

Originally posted by SilentGiant
really?

after I put in the CAI I lost about 50-75 km per tank..

I would think that more air going in, increases the amount of fuel you burn...

I don't know how this would work unless you have a regulator. The air flow change isn't enough that more fuel would be required.

[Skyline_Addict]

CAIs don't increase airflow alot, but they do encourage more efficient airflow of the air that comes in.

[Aleks]

Originally posted by SilentGiant
really?

after I put in the CAI I lost about 50-75 km per tank..

I would think that more air going in, increases the amount of fuel you burn...

Are you sure it isn't the case of you liking the intake noise and givin 'er a bit more than normal. Back in the day I had boltons that was the case with me. LOL

[SilentGiant]

well maybe at first...

but its been on for over a year now...not really the same...more power yes and a worthy mod :)

but still didnt improve gas mileage.

and it wont get any better next month when my headers and exhaust go in ;P

[rice_eater]

my engine with all the boltons gave me a bit better mileage than stock when driving like a normal person (400-450km when driving normal, under 300 when constant WOT). that was with perf computer, cam, bigger tb, bigger head, rebuilt low compression block, intake, header, UDP...EVERYTHING! your mods will make the engine run more efficiently, which could mean that the engine will run smoother, needing less or the same amount of fuel to give you similar or better performance. it works less to give you the same amount of power, therefor balancing out the times when you're at WOT and using a tad more fuel than stock... i dont know, i say go for it and dont even sweat it

[pr0]

Originally posted by SilentGiant
really?

after I put in the CAI I lost about 50-75 km per tank..

I would think that more air going in, increases the amount of fuel you burn...

Unless you are tuning (and suck balls at it) with an AFC I don't see how that is possible. The car isn't going to add more fuel all by itself, that is why turbo guys need some sort of FPR or stand alone to accommodate the increase in air flow.

[SilentGiant]

well if bolt ons are sucking balls at tuning I guess we all suck balls...

Just what I noticed...it might not be fact but I try to keep an eye on my gas mileage since I have to commute 1 hour each way everyday...

[88CRX]

dont think mine really changed... def didnt get better.... prolly since the tune of vtec got alot better = hitting it more often lol

[rice_eater]

Originally posted by pr0


Unless you are tuning (and suck balls at it) with an AFC I don't see how that is possible. The car isn't going to add more fuel all by itself, that is why turbo guys need some sort of FPR or stand alone to accommodate the increase in air flow.

well of course the computer adds and decreases the amount of fuel...it does that constantly to adjust to how you're driving and what you want from it by adjusting the pulse width (injector open time for the noobs). it compensates for your CAI just like it would compensate if you had bad gas or your cat was plugged or whatever. when you get to turbo the demands are so far outside of what the computer can adjust that that's why you need rising rate regulators and other fuel mods. what i'm getting it is that the computer has a small correction window, so it cant possibly spit out that much more fuel than stock

[pr0]

Its not going to make your car run rich enough to have a loss in gas mileage. As stated above by rice_eater, the ECU has a very little correction window so it can't consume that much more than its suppose too.

[PorknBeans]

Originally posted by SilentGiant
well if bolt ons are sucking balls at tuning I guess we all suck balls...

Just what I noticed...it might not be fact but I try to keep an eye on my gas mileage since I have to commute 1 hour each way everyday...

its probably just in your head. haha it should be the same if not a little bit better...

[ShadowDragon]

We've been doing extensive polling over the past two years as to whether bolt on CAI's increase gas mileage and the numbers are leaning heavily towards 'yes'. We've gone through owners of all cars and trucks who've added CAI's or modified intake tubes and more than 75% have reported an increase in mileage. This goes back to the Z duct craze that started in 2003 with G35 owners. The father of the movement, Dave Ochenreider, was looking to increase his hp and for a better sound, but he stumbled upon a great, inexpensive mod that saved him some money on petrol.

[Supa Dexta]

Yeah, I've always thought of it as being a touch better on fuel, but since people love the sound of it, they tend to be on the gas more, and thus using more fuel over all... Usually when you free up some restriction of any kind, it's going to be a help...

:)