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-   -   TJ and 10 MPG? (http://www.wranglerforum.com/f282/tj-and-10-mpg-144516.html)

dw49085 03-06-2012 09:24 AM

TJ and 10 MPG?
 
Hey all, I did not purchase my 2006 4.0 Liter for the gas mileage. However I am shocked that I am only getting 10MPG. I do drive mostly city and one week did more HWY and got 13.5. I have 33's on it and am told that may be why but not sure. I am in my Mid 40's and am not at all heavy on the right foot, in fact I try very hard to not take it over 3 thousand RPM's and mostly stay under 2. I will admit I bought it last Dec. with 30,000 on it and do not think it has been serviced yet. Any advice???

TjWranglerMan 03-06-2012 09:35 AM

Do you know if your speedo gear has been changed for the tires?

spy 03-06-2012 09:35 AM

There is A lot of factors, just make sure she's tuned up good, it's the nature of the beast your driving a brick haha :thumb:

RockHound 03-06-2012 09:41 AM

What tranny do you have auto or standard? I have a 99, 4.0, 5 speed, 35" tires and 373 gears. I average 18 highway, not reallysure around town.

TheTJRod 03-06-2012 09:56 AM

I bet your speedo gear wasn't changed out and the reading is being skewed. Check a GPS against your speed to check.

RockHound- How in the word are you getting 18? I'm getting 15.6 mostly highway. I need to start drafting behind semi's.

TjWranglerMan 03-06-2012 10:33 AM

Yea when I first bought my tj I was getting 10-11 mpg and it didnt seem right since I work about 18 mile away and filled bouts out every Friday and was getting 175-185 to a tank I changed my speedo gear and I'm at half a tank and at 162 miles hopefully I can hit 230+

RockDawg 03-06-2012 11:01 AM

I have an '06 unlimited...When I bought it new, I got 13 mpg at best...regardless of accessories I was running (incl. AC)...now with 35s, 4.88 gears, and the correct speedo gear I get 11 mpg regardless of accessories being used (incl. AC)

woggie 03-06-2012 11:13 AM

Quote:

Originally Posted by TheTJRod (Post 2109496)
I bet your speedo gear wasn't changed out and the reading is being skewed. Check a GPS against your speed to check.

This is the best advice starting out to see what you are truly getting. If the speedo gear has not been swapped out then your odometer will not be accurate which will throw off your calculations. I have 35s and after using the GPS for a couple of tanks to track my miles I was driving close to 10% more miles then the odometer showed which will help your MPG a little.

dw49085 03-06-2012 03:45 PM

Speedo gear
 
Thanks, not sure since I bought it used about the speedo gear. I will take her out tomorrow and run it down the hwy at 60 and see if it takes a minute. Never thought about the gear though, TY!!!

Rubicon06Va 03-06-2012 05:10 PM

Quote:

Originally Posted by RockDawg (Post 2109709)
I have an '06 unlimited...When I bought it new, I got 13 mpg at best...regardless of accessories I was running (incl. AC)...now with 35s, 4.88 gears, and the correct speedo gear I get 11 mpg regardless of accessories being used (incl. AC)

So you bought new, thanks for that info! I get 11 mpg and wanted to know what a new stock LJ get per mile.

hardcoretj 03-06-2012 06:07 PM

Wow! Now I feel good about 16 mpgs with a V8 conversion 4.88s and 32s.

Rubicon1968 02-03-2013 12:53 PM

I get 9-11 mpg- 2006 LJ- 6" lift 35" tires lots of heavy mods it sucks but I wouldn't drive anything else..

sinbob 02-03-2013 01:04 PM

Wow:eek:, I am feeling really good about mine. :dance:It is my DD and the combined averages are, winter 15, summer 16.5mpg. I have 35's, 4.88 gears and 5.5 lift, but I think the 6spd xmsn helps alot

UnlimitedLJ04 02-03-2013 01:04 PM

Quote:

Originally Posted by dw49085 (Post 2109406)
Hey all, I did not purchase my 2006 4.0 Liter for the gas mileage. However I am shocked that I am only getting 10MPG. I do drive mostly city and one week did more HWY and got 13.5. I have 33's on it and am told that may be why but not sure. I am in my Mid 40's and am not at all heavy on the right foot, in fact I try very hard to not take it over 3 thousand RPM's and mostly stay under 2. I will admit I bought it last Dec. with 30,000 on it and do not think it has been serviced yet. Any advice???

Questions:
1) Has the speedo been recalibrated for the larger tire size? This involves a speedo gear change for non-rubicons, and an electronic device for rubicons.

2) have you check the O2 sensors and cats for problems/clogs?

3) check the normal culprits...air filter, throttle body, IAC, etc. have you shined a flashlight down the throttle body to see how dirty it is? if it's dirty, clean it.

FWIW, I can get anywhere between 13mpg to 19mpg depending entirely on driving style & conditions. 4.88s w/ 33s & correct speedo gear.


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