I bought a Skinny Pedal intake and have had it on for about 2 weeks now and am getting worse gas mileage then with the stock intake. i dont have any engine mods. Only the intake and a 1" mml. Im running 33x10.50x15 have a 2.5" RC lift and 1.25" BL. Wanted to see if anyone had some advise on what i could check or how y'alls gas mileage did when you installed the intake. Thanks

What year?

05

That is strange since you are giving the engine cooler and more combustion air. Is the decrease due to you being heavier on the pedal or is this consistent over a few fill-ups?

Here is the thread regarding mpg with the MCAI http://www.rubiconownersforum.com/phpbb3/viewtopic.php?f=23&t=58612&hilit=mcai+gas+mileage

mine went up... however that only happened after I learned how to keep my foot off the Skinnypedal (gas pedal... not Josh). once this mod is done a 1-2 MPG increase is about the norm.

i shift at 2 grand or less and keep it around 65mpg on the highway. ive on;y filled up a couple times now. im gonna keep track of how much mileage i get with ever fill up and see what i get.

This is really interesting. I don't recall a drop in mpg related to the Skinny Pedal, aka MCAI, reported before. I documented a conservative 1 MPG increase which saved me over $500 in a 4 month period of long commutes.

As mentioned above, resist the urge to get frisky with the "skinny".

yeah , for the first couple days i got "frisky" with the gas, but the first fill up i was gentle with it. The whole reason i got the intake was to save a couple pennies on gas. im about to fill the tank again so im gonna write down the mileage and see...........

The question is are you using your AC more now that it is hot. I know i lose some MPG with AC.

I have the MCAI on both my 04 TJ Rubi, and my 06 LJ Rubi. In both cases I saw a slight increase in MPG. The issue may be your computer is relearning fuel to air ratios and has not optimized everything yet. In both cases it took a bit of driving to plateau out the mpg.

Since your rig is an 05, it is an 04 build date? The only reason I ask is where is your Idle Air Thermostat?

Is it in the air tube or in the manifold? (I put tape over my old one)


Here is my writeup : http://www.rubiconownersforum.com/phpbb3/viewtopic.php?f=39&t=68800&hilit=mac+cold+air+intake

i live in texas so ive been using the ac for awhile. its normally on low and on the "circulation" mode ( i guess thats what you call it). And my idle air thermostat is in the air tube.

i filled up my tank and headed to corpus cristi. its about a 4 hour drive. and i still am gettin crappy mileage. i averaged about 14.5 mpg. before the intake i averaged 16.5. i dont know what im doin wrong. i used cruise control. set it at about 70mph 2100 rpm. HELP!!!!!!!

I am afraid that your situation is so unheard of, obviously rare and unusual that most people probably do not know what to say or even what to think of to look at. Much less WHY this would be the case in your situation. I know that is the trouble I am having.

Are you sure that everything has been installed correctly, and nothing would be blocking or hindering the flow of air to the engine?

Do you have any install pictures of inside the cowl?

You might have a leak in the Air intake system itself. If it is not drawing from the MCAI solely then you can get effected airflow. When the system is properly sealed you should see an increase. Of course there are many things that can effect your mileage. It could be something else effecting it, and it just so happened to show up right at the time that you did your MCAI

i can get pics, but im new to the site and dont know how to post them. as for any leaks....im gonna look over everything again and get back to you. i dont know if this matters but my engine temp is at 210. is that the norm?

210 is normal.
Here is gregert12's instructions for posting pics on here using photobucket

i was talkin to someone and they suggested that i put a new muffler or glass pack. Anything that would give me better exhaust flow. Any thoughts???

While that COULD give you a very slight to moderate improvement in MPG (maybe 1 MPG at most) it still does not address why your experience with the MCAI/SkinnyPedal system is different than every report I am aware of on ROF. A new muffler or catback system is a nice upgrade, most do it to free up room rather than MPGs in instances that control arms start interfering with the OEM muffler during flex off road. What I said above about getting maybe 1 MPG might be on the conservative side. That said, I would NOT buy into ANY sales gimmicks that you often see with a catback system saying you'll get 5-10 or whatever more MPGs over stock. What you could expect to see, hear and feel depending on the route you go is 1) more room under the jeep, 2) a sound that might be more appealing to yourself and/or friends, 3) a bit more torque. Not a ton more torque or anything... But just enough that you'll be able to feel or think that something is a little different. But this is JMHO.

That said... I am a fan of the flowmaster hushpower stainless steel mufflers.

if this is who i think it is i know the setup was installed correctly.....i installed it Double check the cowl drain filter area, the black plastic part on the bottom that the filter was put on top of. if it pops loose then you could have drawback of air from the engine side. and did you put a good clamp on the throttle body side of the tubing?

out of the 4 or 5 i've installed this is the first i've heard of losing mileage. i know it sounds silly, but make sure you fill up at the same station and pump if you can. also give the heep a good shake side to side in a rocking motion to make sure you get the air bubble out of the tank that might be there. the reason behind all of this is to make sure your getting an accurate fillup each time. if not then your calculations could be off.

Yes Jimmy it is Rico. I told him to come to this site for a better reference. Maybe Josh or Mac could better assist him. He's running 33x10.50 km2's on the rocky mountain edition. Meaning he's got the 30/44 combo. Which is a 3.73 gear I believe. He has recently added the hardtop, but I don't think that'd affect his mpgs.

Yes Rico the better air flow in and out of the motor it's possible to see an increase, but I doubt by much. The cheapest fix might be changing spark plugs?

true, could've just been the install was a coincedence on the issue.