Hi gang . My first post about my first Civic, an '06 EX Coupe 5-speed. What [if any] effect does a CAI have on gas mileage? I did an archive search but didn't find anything. Thanks

 

With an intake, you'll actually see better gas mileage.

 

i have a 93 dx with a 1.5 with a short ram i gained almost 2 mpg

 

i think forty was running in the high 30s, low 40s on the higway with a CAI and aftermarket exhaust...dotn quote me on it tho.

 

When you say "aftermarket exhaust" do you mean cat-back? What's the difference between cat-back and axles-back? Does just adding a muffler [DC Sports] add any power, or just a nicer tone. It looks like my budget is going to cover an AEM CAI and a muffler.

 

cat backs are all the piping from the catalytic converter back...cat..back...get it?

axle backs are just that...from the axle back. its basically the B-pipe and muffler of a catback. they wont add any performance.

a muffler wont do anything to your car except make it sound like enormous *******.

 

but unless your running a pretty modded engine a cat-back doesn't add much performance either. cat-backs sound worse than an axle-back because you retain the stock resonator. cat-backs lose more in the bottom end...they dog more

 

Let me see if I've got this straight. A CAI adds power, performance and sound. Adding any exhaust short of a header adds nothing else but noise if the motor is stock, right? I'm an old guy [44] who just wants a little more power and would like to hear it. I won't be swapping in a K20 [I have no idea what I just said] and dropping it 3 inches....yet!

 

it will too add power. its one of the first things anyone ever changes on their car for the moderate gain at a fairly cheap price.

4-2-1 and 4-1 headers are the two basic designs.

a 4-2-1 (also known as a 'tri-y') takes the four exhaust ports, converges it into two pipes, than converges the two pipes into one...like this:


a 4-1 takes the four and converges them down into one pipe all at once..like this:


normally (doesnt always apply...), a 4-2-1 header will give you more low-mid range power. a 4-1 header will give you top end power. general consensus is 4-2-1 is for autocrossing adn street driving and 4-1 is for drag racing.

exhausts will add more power than an intake or header...usually about 4-8. they basically make flow less restricted...so its like blowing through a coffee straw (stock exhaust) vs. blowing through a mcdonalds straw (aftermarket exhaust). one thing you wanna be careful of tho is you dont want to go too big...because then you can lose exhaust velocity and actually lose power. its like blwoing through a paper towel roll...only not quite that extreme...

a K20 is a honda engine...and one helluva sweet one too.

dont drop it 3 inches...ever .

 

yup, 38.6mpg average, and that was with a few really good 60-90 pull passes on the two lane highway. AEM CAI, stock header/dp/cat, and Megan Racing 2.5" cat-back on a 56k mi engine. I know I could have hit 40mpg if I could keep myself from getting on it so hard