ok i know a decent amount of mechanics as to know what does what and can improve on an engine, but i got into a debate at work on CAI's with this import guy saying that CAI do not in any way improve gas millage and actually reduce it. I disagree with him, only in the sence of maybe a 1 mile improvement, but my argument stands that it can improve (and of course how you drive the car). So i need some technical advice here and facts to back to this up, because i dont understand how it works. is it that if there is cold air the volume of air fills the piston chamber up faster or more then the gasoline? please explain someone

That has been a ongoing subject. If you read some of the other threads on the subject, you can decide for yourself. I think the K&N CAI is less restrictive than the stock airbox. Better air flow means better performance.

Real world data would indicate that there is a mild increase in fuel economy. I know that this does not necessarily jive with my PM to you, andyx181x. However, when my K&N Air Charger was the only modification involved, I saw the fuel economy increase. Perhaps that was due to the K&N, or perhaps it was due to breaking-in the engine. I can't say for sure.

-K

I have a suggestion. Check your car's mileage. Then go buy yourself a CAI and install it. Then recheck your mileage. ;-)

mechanic thats the obvious idea, lol i just need opinoins to back this up because i do believe they work just not like huge results

I would be very skeptical about noting any major OR minor improvments, really. It is the auto manufacturer's duty and obligation to make the most fuel efficient cars as possible. If something this simple made improvements to the fuel economy, then they would have implemented it at the factory. Chew on that.

ahh thats what im talking about, now thats an answer lol. but then again if CAI really do offer improvements, why dont car companys install their own versions into the cars then using this restricting air boxes?

*I* really don't think the factory air boxes are that restrictive. I think that's a buncha hype. Honestly. Have you ever witnessed a flow test comparison, or even seen data? I haven't. Its all he-said-she-said bullsh!t. I have never installed a CAI. When I go to the racetrack with a car that has a similar setup, all I do is remove the air filter and block or disable any hot air ports to the factory box. Works fine and looks 10 times better in most cases.

hmm well the question is still debated then

*I* really don't think the factory air boxes are that restrictive. I think that's a buncha hype. Honestly. Have you ever witnessed a flow test comparison, or even seen data? I haven't. Its all he-said-she-said bullsh!t. I have never installed a CAI. When I go to the racetrack with a car that has a similar setup, all I do is remove the air filter and block or disable any hot air ports to the factory box. Works fine and looks 10 times better in most cases.

In general, it's not so much the factory airbox that is restrictive, but the lack of cold air being supplied to the airbox. Or the location is in a heat soak area. Factory paper elements are restrictive. The reason the factorys in general don't make CAI intakes are really two fold. 1. They have to comply with Federal noise standards. 2. They have issues with idiots hydrolocking the engines under warranty. Chew on that.

Good point on hydrolocking, I completely forgot to mention that also. Most factory air boxes are designed in a curious manner at first glimpse, but if you study them long enough, it will dawn on you that they are made that way to help thwart large quantities of water from entering the intake.

I noticed the fuel consumption was worse. Of course I also noticed that my right foot got heavier on the gas pedal too...........:D

I didn't notice a big diff in gas mileage just driving around after I put the CAI or the Headers on. I did notice a difference in the way I drive though......

Andrew

I just put the K&N drop in filter and have noticed nothing, I must agree with mechanic58 that the stock box is well designed and works the best for street driving, with that said the better you make her breath the more efficient she will be. I say we send a letter into the Mythbusters and have them prove it.

That sounds like a cool idea. They already busted the A/C or windows down myth. This would be a good one too....

I think the only way it make a big diff is with all out racing. If you don't take a baseline, then it is really hard to see or feel a difference.

Andrew

I never use CAI I do use the K&N drop in filter chager,after watching a test on Motor week where Pat Goos tested both systems on a Truck Found that the CAI drew too much hot air from the engine bay area, but the K&N drop in did give 20 more HP at full throttle then stock. Forget the date of the show but it might even be archived.

A CAI will help gas milage with a proper tune..

it will increase your mileage, but not by a lot. The more cold, dense air you add to the fuel/air mixture, the better the fuel burns, thereby using less fuel.

an intake won't improve mileage with a tune. a tune in itself might but unless you're running at wide open throttle it isn't going to make any difference. at WOT these cars are tuned a very rich AFR but at normal driving the front O2 sensors keep the air fuel ratio at stoich (14.7 #s of air to 1# of fuel) no matter what the tune. also the more cold dense air you pull in will cause the computer to also bring in more fuel to keep the ratio the same. you may have the gas pedal not quite as far down to maintain the same speed (it would be imperceptible) but you're burning the same gas. the only way any kind, including stock, would be affected at normal driving is if the filter is plugged.

an intake that lets in more air at WOT burns MORE fuel keeping the AFR the same and thus makes more power. i have the data of it with different intakes too using MAP (manifold pressure) which relatively shows how restrictive different systems are. LPE and K&Ns give about a 4 kPa pressure drop at high RPM WOT runs, Volants are worse. the stock box is even worse with a 6+ kPa drop over 6,000 RPM. my direct shot OTRCAI averages 1.4 kPa over 6,000 RPM