Engine Air Filter or Cold Air Intake

Air Filter or Cold Air Intake

I've heard using K&N Air Filter improves your fuel efficiency. Does Cold Air Intake do that as well and even more than just merely replacing your air filter?
Also, since there's so many vendors out there, what would you all recommend for Cold Air Intake?
I'm currenty looking at 3 vendors : TRD, K&N, and AEM. Any thoughts?
Thanks

what car do you have?

2005 Corolla S

i think adding a CAI will only hurt your gas mileage if you drive your car hard..

^ i always thought it improved their fuel economy

I noticed a mpg gain. More flow + cooler air = more fuel to air ratio + better burning efficiency.

more burning = more hp = less gas mileage?

^ true...but its cooler cleaner air your adding? i dunno i still say he should go with the trd cai

more air = more gas = more power = less gas mileage

but dont they spend years of R&D and hundreds of thousands of dollars to get the corolla to be a gas saver? just my 2 cents...

Well you need to take into consideration the cost of extra parts. I don't think they would spend so much time and money to increase the gas mileage even more of an already fuel efficient car.

ok, im gunna get technical with this. so be patient.

Inside your exuast is an o2 sensor. It measures your air to fuel ratio. There are 2 types of sensors. Wide band and Narrowband. The one you have in your corolla is a narrowband. Now when you are crusing along doing a constand speed, this narrowband sensor is active. It sniffs the air and sends a signal back to your ECU letting it know if the engine is running lean or rich. The optimum level of Air to Fuel is 14.7 at cruising speed. If the sensor sends back a lean signal, it will add more fuel, if its running rich, it subtracts it. So in this case, if you add more air to the equation, you add more fuel.

Now, when you are taking off from a red light, and your flooring it shifting thru the gears, your narrowband sensor is shut off. Your ECU enters a mode where it uses pre-adjusted fuel maps. These fuel maps are tuned to run rich. When you are hauling it down the road, you want a bit more fuel into the engine to produce more power and to help keep things cooled down. Now, you can only inject so much fuel before you start loosing power. Our engines run pretty damn rich in this mode. So you are actually loosing a little bit of power. These fuel maps in this stage hardly change. Since your o2 sensor doesnt sniff the air in this mode, this is where the cold air intake can help you. Since your engine is already running rich, when you add that intake, you are adding more air to the equation, but keeping the same amount of fuel. Thus you are leaning out the AF ratio a little bit and getting more power.

So, in cliffnotes, when you install an aftermarket intake, you will get more power. However, you will also be using a bit more gas.

all a car needs to be a "gas saver" is la ight weight body, and a small engine.
Look at the corolla, a compact body with a small 1.8 litre engine
Camry is a bigger more full sized body wtih a 2.4 litre engine.

Both have about the same power/weight ratio, however the corolla is much more efficient with gas because it doenst have to haul around as much weight, and the engine can only take so much gas.

the bigger the displacement, the more fuel its gunna use.

so.... the ECU ignores the O2 sensor in 75+% throotle or 90+%?

im not sure when exacally it starts ignoring the throttle. I think it has to do with the engine load, not throttle. But, i really dont know about that. I just know how the open and closed loop system works.

IMO, buy your exhaust system first. Doesn't the 05' Corollas have drive-by-wire?

I believe so. Very few new cars actually have throttle cables.

driveby wire?

Electronic throttle control. No throttle cable.

ohhh, yeah i suck at this sorry for asking questions...does that give better throttle response?

like lets say my hatch and its <100 hp engine?

lol i learned alot from you sky.. i got my lesson for the day!

Drive by wire sucks! My moms camry has it. It works when it wants to. Sometimes Ill have my foot glued to the floor and nothing and when I tap it, the thing flies lol. Im happy that mine is hooked up straight to throttle and thats how it should be.

Think about it this way: what's faster: pushing a button to open a valve, or pulling a cord to directly manipulate it?

that makes sense...how would it effect what kinda intake he should buy though?

lol^

screw you vibe, go to bed!

haha LOL @ everyone

lol it sounded like you were sarcastic in that post

yeah i dont rly get it but whatever ill figure it out later, i was just messing around with you though

You mean drive by wire? Here's an analogy: Cordless phone vs. traditional phone. Everything else is the same so the intake won't be affected.

some of the folks over at 9thgencorolla are using SRI/CAI from Cosmo Racing.