ilovejdm

Just curious, done some searching but cant find what I want, Wondering if an aem long ram and like 2.25 piping to a es tuning can will hurt my gas mileage or help it on the sohc? Trying to get as good mpg as possible but never really remembered to check my gas mileage when I had a sohc and gas was cheap.

Eye8Pussies

the intake and exhaust will theoretically help gas mileage, as it helps the engine breath easier and let its exhaust out easier as well

BUT the tough part is that once people install an intake and exhaust (either or), chances are that they drive their car a bit harder and a bit faster than before to hear the sound....which hurts gas mileage.

And also, you may lose some low-end torque (not so sure about small engines, since I'm familiar with v6's), and you may then use more throttle to get the car going, which would then also use more gas.

But yes, in theory, it can help gas mileage

ilovejdm

hmmm....what to do, what to do....

ilovejdm

i also hear if you put too much of a free flowing exhaust that you lose gas mileage because of not enough back pressure, which too much free flowing you do lose low end torque like when running open header for instance, I guess the thing to do is find the right combination of intake and exhaust, course after you get done with all of this, how much mpg are you really gaining? spend $350 for 2 mpg gain? not worth it.

offcamber

if you add much more than an intake, your better breathing engine will tell the ECU its leaning out. your ECU will then over-compensate (to be safe) and run richer, thus making your MPG worse. it will also slowly harm your engine. the solution would be to get it profesionally tuned=not worth it with just intake and exhaust.

you can get away with an intake, but it will only help your perf., not MPG's.

don't freek out, if some of you have intake/exhaust, it won't hurt it that much, especially if you don't have a header. when you do go all out and do I/h/cat/E, get it tuned for better performance and gas milage.

ilovejdm

I think the best thing you can do for gas mileage is tire pressure, tune up, and easy driving.

I don't think an intake and a muffler would hurt it tho as long as you dont drive like an idiot.

Alot of times putting a free flowing cat helps out too because after years the original cat will become clogged up.

EK_B

Save the hundreds from the intake and exhaust for expensive *** gas.

ilovejdm

ha! Good Common Sense Right There!!

austinkli

mostly, better performance equals worse mpg. but in the case of just an intake and exhaust, i wouldn't think you'd really notice it. i did it, haven't noticed a difference either way really. that's a lie, i have worse gas mileage, but only because i like the sound of that intake when i accelerate. but my room mate gave me my intake, otherwise i'd not have spent the money on a sohc for a performance or mpg increase.

oneludesol

your best of both world gas mileage solution is a K&N or better drop in filter (no extra noise so you will be a good little boy), 5w 20 oil change, high flow cat on STOCK EXHAUST, give it the full seafoam treatment, a stock tune up, narrower tires at higher pressure, and some aerodynamic mods (i wont get into specifics unless you are really interested).

With this, I got about 7-10 extra MPG out of a civic lx, 7 no matter how I drove, and 10 driving/shifting like grandma and not going past 60mph yes even on the interstate, which I would venture to say could even have given more mpg if I had taken the time to measure the economy on interstate only... no ****.

austinkli

seriously? wow, i don't have that kind of restraint. I'm no ricer, but i like the sound of my intake so i probably accelerate faster than absolutely necessary and i would probably be doing 70 to 75 on the interstate without even noticing.

oneludesol

you would simply be amazed by how much wind resistance can affect you gas mileage especially over 60 mph... in fact some states are toying with the idea to lower interstate speed limits to 60 to conserve fuel.

ilovejdm

high flow cat on stock exhaust helps mpg? no ****? I didn't know that, and aerodynamics? I got a type r lip and its dropped 2.5 inches, is that what you mean?

ilovejdm

oo and do you think cutting off the resonator under the car on stock exhaust would help?

How about the intake resonator and just run the airbox with a k&n filter...which I am right now

austinkli

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ilovejdm &raquo;</TD></TR><TR><TD CLASS="quote">high flow cat on stock exhaust helps mpg? no ****? I didn't know that, and aerodynamics? I got a type r lip and its dropped 2.5 inches, is that what you mean?</TD></TR></TABLE>
without the whole exhaust system, headers, intake, catback, all of it, i don't see how personally, but i won't say he is wrong. I've never tested it or seen literal proof to back it or disqualify it.

oneludesol

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by austinkli &raquo;</TD></TR><TR><TD CLASS="quote">
without the whole exhaust system, headers, intake, catback, all of it, i don't see how personally, but i won't say he is wrong. I've never tested it or seen literal proof to back it or disqualify it.</TD></TR></TABLE>

any moderate reduction in backpressure is going to help, especially with a reduction in restriction on the intake side as well... I would say that maybe a header too would be good, but you want to avoid doing the whole exhaust system as it will get louder and may encourage different driving habits.

as far as aerodynamic mods go, the car was dropped 2" when i started so i dont know, but i dont mean a lip or body kit... I mean modding the front bumper to a solid (no holes) filling in the cracks of the fenders, filling in the molding of the windshield, and fabbing some rear wheel covers (think honda insight)... Make it look as close to a drag car with a lift off body as possible without rendering it unstreetable for best results.

ilovejdm

ooic...now that I realize what your talking about when you said aerodynamics I feel like a dumbass for saying type r lip? haha

oneludesol

hehe i understand, there is not a whole lot of discussion about modding like this, but I do know of a 93 vx that is getting almost 70mpg with these exact mods, plus some kind of "pintle" style fuel injectors (i believe its the whole manifold too but im not sure)...

ilovejdm

haha yeah, I gave up on going fast for a while till I get out of college, I'm all about the mpg's now! hp is for f*gs.