Gas Mileage...NEED HELP!!!
#11
JK Super Freak
Try a K&N aircleaner element or something similar. A free flowing exhaust would help as well though with that long of a drive you might not like it after a while. A tuner would help as well as a Viper TB. Ensuring your tires are porperly inflated will help as well. Regearing helps as well but I am sure it would takequite some time to recoup the expense of that. BTW, many here will tell you "don't fear the gear" but be careful with that. I was getting 17 hwy with 3.73s and 37s on my 08 JKU and when I regeared to 5.13's it DROPPED to 15.5. That was with the above mentioned mods so I know my calculations were accurate. I think with those 37s I would have been better off with 4.88s though you will find many here will disagree with me.
I think with your current set up I think you would be best with 4.56s. Many here will disagree with me and quote a chart a forum member made but personally I think that chart is wrong as your motor will be turning faster than it needs too and that costs fuel. I say this because of my experience with the 37s and 3.73s and then 5.13s with a drop of 1.5 mpg with that change. I know a few other members (Cdyspeed) went by that chart and feel it is wrong also.
I think with your current set up I think you would be best with 4.56s. Many here will disagree with me and quote a chart a forum member made but personally I think that chart is wrong as your motor will be turning faster than it needs too and that costs fuel. I say this because of my experience with the 37s and 3.73s and then 5.13s with a drop of 1.5 mpg with that change. I know a few other members (Cdyspeed) went by that chart and feel it is wrong also.
#12
How are you calculating the milage? Are you trusting the built-in computer or are you making your own calculations based on distance traveled and the gas replenished at the pump? Did you recalibrate your speedometer?
I have the 3" lift, but stock rubi tires. I drove it on my daily commute a couple weeks ago and per the built-in computer I averaged 19mpg for the round trip which includes some big socal mountains. I drove no faster than 70.
I wouldn't consider driving it more than a couple trips per year. My commute is 130 miles round trip. My Corolla gets 38mpg. I just replaced all the tires for $450 and they will last 80k miles. The gas and maintenance cost difference will easily pay for a more economical used commuter car and you will like your Jeep more when you do get to drive it around. The Jeep is my wife's DD.
I have the 3" lift, but stock rubi tires. I drove it on my daily commute a couple weeks ago and per the built-in computer I averaged 19mpg for the round trip which includes some big socal mountains. I drove no faster than 70.
I wouldn't consider driving it more than a couple trips per year. My commute is 130 miles round trip. My Corolla gets 38mpg. I just replaced all the tires for $450 and they will last 80k miles. The gas and maintenance cost difference will easily pay for a more economical used commuter car and you will like your Jeep more when you do get to drive it around. The Jeep is my wife's DD.
#13
JK Junkie
Join Date: Nov 2010
Location: Whitefish,Montana
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Originally Posted by crazygrady127
SOUNDS LIKE YOU NEED TO RE-GEAR IT !! iM RUNNING 37'S WITH 513 GEARS AND ON A GOOD DAY , AND NO WIND , I GET ABOUT 17.8 MILES PER GALLON !! I HAD THE SAME PROBLEM WHEN I HAD THE SAME SET UP AS YOU , IT FELT LIKE MY FOOT WAS TO THE FLOOR THE WHOLE TIME I WAS ON THE E-WAY !!
#14
JK Newbie
Join Date: Oct 2010
Location: Madisonville, TN
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There are some things you will find true to "gas mileage" affects on all JK Jeeps, no matter what engine. Lifting 3" will net you NEGATIVE 1 to 2 MPG. Running 35 inch tires and wheels will have the same NEGATIVE effect of 2 to 4 MPG. Bumpers, wench, skid plates and gear will also net you NEGATIVE 1 to 2 MPG. Do the math, this will take a JK that can get possibly 20 MPG from the factory into the average 12 to 16 range in MPG according to the mods performed. Of course this is related to your location (atlitude and geography) and driving habits. It is the extra weight, tire diameter and wind resistance causing the MPG loss, all physics laws that cannot be avoided. Most modders then regear and perform engine performance mods (i.e. ECU programming, superchargers, headers etc.) to get the engine back into it's power band and better operation efficiency to account for this negative physics effect. It is a reccuring theme in most of the post in this forum that give truthful feedback about MPG, I expect 2012 JK to be NO different. I expect you will get nearly 20 MPG in factory form fully broken in but when you start modding you will see the MPG hits as I have detailed. I have experienced the same with my 2008 JK "X" that gets 16 MPG running a 3" lift, 35" BFG's, Gibson exhaust, VIPER Throttle Body, Hypertech "REGULAR" tune with extra weight (see profile). I commute 500 miles weekly.
#17
JK Enthusiast
Join Date: May 2010
Location: Lowell, AR
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Originally Posted by Rhino64
You're driving the wrong vehicle. Gas mileage has never been a strong point for a Jeep you should have known that for the start.Like one poster suggested spending $1900 and maybe gain 2mpg hardly justifies the cost IMO, just bite the bullet or find another ride.
You never come out ahead spending money for mods to increase fuel mileage. It would take you 20 years to get back that $1900 with only a 2-3 mpg gain.
#19
JK Junkie
Join Date: Jul 2008
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$3.25 per gallon / 16 mpg X 100 miles per day = $20.31 per day
$1900.00 / $2.90 = 655 Driving days to break even
#20
ive got a 2011 wrangler 4dr sport, with 35" bfg mud terrains and 3.73 gears.. i drive 99.9% highway basically all flat, one hill.. i baby the jeep due to the fuel economy as im lucky to get 280 miles per tank.. and im in the 14-15mpg(according to the computer).. does this not seem pretty low? and if money is tight, what would be the better option.. regear or a chip?