MPG Issue/question?

JKHunter817

JKHunter817

New member
I am fairly new to the jeep game but I'm not sure if my mpg are correct or close to what I should be getting any help would be great! I've read everywhere "it's a jeep" but there has to be a better answer ha thanks in advance here is what I'm running .

The AVG ECO reads 13.3-13.4 at all times street or hwy

2008 Rubicon 6 speed
3.5" lift
35" tires (30psi)
Walker quiet flow exhaust
AEM intake w/ a random velocity stack (came on the jeep)
87 gasoline

I do have the gascap reading and check engine light P0456,P0457 Evap issue I need to figure out. But could this be the reason for low mpg? I have seen others getting more with similar rigs. Thanks in advance.
 
Mike_JK_Houston_711

Mike_JK_Houston_711

New member
Doesn't sound too out of the ordinary. I would invest in a procal module if you continue to do things to your rig. You can update the computer every time you change any elements - tires, lift, gears, even your low air tire gauge.
 
JKHunter817

JKHunter817

New member
Is the procal the only module I can use to eliminate the sway bar light as well? I never had problems with it until I put on my sway bar end links and now it stays flashing
 
ScoobyCarolanNC

ScoobyCarolanNC

Active Member
You mpg seems good. The procal will let your computer factor the 35s in which will tweak your speedo & mpg a bit but likely nothing dramatic. If your jeep had a gear swap, that will factor as well. All it does is change the numbers in the computer so they're correct, it's not a "tune".

Your swaybar is a different story...
 
Mike_JK_Houston_711

Mike_JK_Houston_711

New member
I don't think the procal will fix the sway bar light. You might want to reset the battery. Disconnect the positive and ground it to negative for 30 seconds. Then reconnect to positive again. Then turn your iginition on, but done start your jeep. Turn headlights on and off. Then turn ignition off. Should reset the computer back to factory settings. I did this just the other day and it worked.
 
10frank9

10frank9

Web Wheeler
JKHunter817 said:
Is the procal the only module I can use to eliminate the sway bar light as well? I never had problems with it until I put on my sway bar end links and now it stays flashing
Click to expand...

What endinks did you install? The only reason your sway bar light should be flashing is if you are disconnected OR your harness is torn, unplugged or otherwise malfunctioning.

To answer your question, yes the pro cal is the only way to shut off your light. But you should only do that if you have replaced your e-disco with a manual version. Diagnose your issue first!
 
JKHunter817

JKHunter817

New member
Ok makes sense, I have the rubicon express end links they were actually for rears but the ones it came with were pointing the sway bar way down these actually make it a tad bit higher than horizontal which I read is ideal? Unless it's different for the rubicon, maybe my lift is higher not sure but it seems correct
 
10frank9

10frank9

Web Wheeler
JKHunter817 said:
Ok makes sense, I have the rubicon express end links they were actually for rears but the ones it came with were pointing the sway bar way down these actually make it a tad bit higher than horizontal which I read is ideal? Unless it's different for the rubicon, maybe my lift is higher not sure but it seems correct
Click to expand...

Yes you still want them slightly above level (if that makes sense). They are fixed sway bars right? I only ask because some UNNAMED shop installed quick disconnects on a rubicon! :doh:
 
JKHunter817

JKHunter817

New member
Haha yeah they are the fixed ones, I was going to order another set for the rear sway bar but they still won't even make it sit horizontal, not sure why or is the rear different.
 
Desert Crawler

Desert Crawler

New member
10frank9 said:
Yes you still want them slightly above level (if that makes sense). They are fixed sway bars right? I only ask because some UNNAMED shop installed quick disconnects on a rubicon! :doh:
Click to expand...
And what is wrong with that. Wouldn't it just let you choose between electronic or manually disconnecting them?
 
Kyle7R

Kyle7R

New member
JKHunter817 said:
4.10 whatever came in the dana44 on the rubicon
Click to expand...

Verify the 4.10's if you can, but the MPG's don't sound too far off.

I get about 14 around town with a similar set up, (6 speed, 4.10's, and 35's) on our road trip earlier this month I came in right around 14-14.5 MPG's
 
JKHunter817

JKHunter817

New member
I'm not too sure how honestly 🤔 but I did reset it for the first time and drove like an old man keeping it under 2500 rpm and it was reading 16.5 we will see how long that last hah
 
Kyle7R

Kyle7R

New member
JKHunter817 said:
I'm not too sure how honestly 樂 but I did reset it for the first time and drove like an old man keeping it under 2500 rpm and it was reading 16.5 we will see how long that last hah
Click to expand...

Unless you've re-calibrated for the larger tires, that is not going to be 100% accurate either, FYI.
 
DWiggles

DWiggles

Caught the Bug
JKHunter817 said:
I'm not too sure how honestly 樂 but I did reset it for the first time and drove like an old man keeping it under 2500 rpm and it was reading 16.5 we will see how long that last hah
Click to expand...

Lift the rear tires off the ground and turn the drive shaft, for every 10 turns of the drive shaft, the tire should turn 4 revolutions if you have a 4.10 ring & pinion :beer:

Your mpg sound spot on. thats right about what I had before I regeared. Only I was running 37s on the factory 4.10 gears and 6 speed :thumb:
 
JKHunter817

JKHunter817

New member
Oh ok , I do need to recalibrate and I will check my gears as well. I had an Infiniti g35 coupe that weighed almost the exact same as the jeep, and the mpg were almost the same. Atleast I'm getting the use and fun out of this one
 
Kyle7R

Kyle7R

New member
DWiggles said:
Lift the rear tires off the ground and turn the drive shaft, for every 10 turns of the drive shaft, the tire should turn 4 revolutions if you have a 4.10 ring & pinion :beer:

Your mpg sound spot on. thats right about what I had before I regeared. Only I was running 37s on the factory 4.10 gears and 6 speed :thumb:
Click to expand...

This :thumb:

I also was able to verify what mine came with using this VIN equipment listing lookup I found when I bought my Jeep.

http://www.jeep.com/webselfservice/jeep/index.html?screenName=customer&country=us&emailUrl=goToEmailForm%2528%2527R%2527%2529
 
FLKEYSJK

FLKEYSJK

Member
DWiggles said:
Lift the rear tires off the ground and turn the drive shaft, for every 10 turns of the drive shaft, the tire should turn 4 revolutions if you have a 4.10 ring & pinion :beer:
Click to expand...

I thought it was that with one rotation of the tire that would rotate the driveshaft a hair more than 4 times to equal 4.10 ratio? I just want to make sure I have it right because I'm not sure if I have 3.21 or 3.73 gears.
 
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