Need some advice?

[Ktmguy23]

I just recently bought a '07 liberty sport 4x4 with 15,500 miles. Since I have had it I have been tracking my fuel mileage and have been getting about 12-14 mpg. I think that is totally crazy, I could have bought a Suburban and done better on gas. I have checked all the usual stuff, tire pressure 35psi, clean air filter, changed oil to Mobil 1. Most of my driving is highway with some city mixed in. very easy with the gas pedal try not to go over 2-2500rpm.

I filled the tank all the way full last week and tonight when I went out I had gone 45 miles since and was just about 3/4 full. I filled back up to full using the same pump and put in 3.7 gal = 12.1 mpg. This is not even close to the advertised numbers or what alot of you seem to be getting.

My question is do I have a reason to take it to the dealer and have it looked at. In my opinion there is no reason for this kind of mileage even with winter gas. This is a relatively small vehicle with a mid-size motor. Thanks is advance for the help.

 

[tjkj2002]

Many factors for bad mpg's,winter fuel,longer war up times,longer till the engine reaches operating temps(affects big time with the O2 sensors),terrian(hilly,flat,use 4wd and such),and city vs highway driving.If you done all the tune up stuff,try another brand of gas,but 12-14 isn't that bad if all city driving in the winter time.granted I'm heavier and modified I only get 8-9mpg's,lucky to get 16mpg's in the summer on the highway.liberty's are no gas saver vehicle,very heavy and the lack of low end torque makes that engine work harder thus lower mpg's.I have never seen anywhere close to the advertized mpg #'s in my KJ.

 

[jeepkj02]

The dealer will probably give you crap, and try to sell you a bunch of worthless packages. The only thing you can really do, and you said you already did, is check air filter, tire pressure, too early for a tune up, make sure your up to date on your maintenance. At 15K, you should have replaced the air filter and f/r diffs. Also, try using a fuel system cleaner. I like to use seafoam every 5-7,000 miles. 1/2 can in your oil (200 mi before change), 1/2 can through the brake booster, and 1 can into a full tank of gas.

 

[Ktmguy23]

I can not in my mind come up with a logical reason that a full-size 4x4 pickup with a v8 gets considerably better fuelmileage than this small suv with a v6. I don't mean to beat a dead horse with this mpg thing but 12mpg is not acceptable nor reasonable.

 

[BoyNamedSue]

I would say something is wrong. I have an '07 also. I would easily get over 20 if highway driving, and 16-18 city driving. It has gotten worse now because Oregon has switched to some stupid ethanol blend year-round now. I haven't checked lately, but it's still not as bad as what your experiencing.

 

[tjkj2002]

I can not in my mind come up with a logical reason that a full-size 4x4 pickup with a v8 gets considerably better fuelmileage than this small suv with a v6. I don't mean to beat a dead horse with this mpg thing but 12mpg is not acceptable nor reasonable.

Better power to weight ratio is why,then again I haven't known anyone with a fullsize pick-up get better then 14-15 combined mpg's to start with,unless they had a oil burner in them.All of my buddies back home in SD all have fullsize pickups,the only one to get over 14-15mpg's combined has a '02 SuperDuty with the PowerStroke(and only when not towing).

The KJ is a 4000lbs SUV with a 210HP V-6,and makes that # at a high rpm.Most 1/2 ton pickups now days have a 300HP+ V-8 and are about 5000-5500lbs,but the V-8 make much better low end torque which helps out.

If the check engine light is not on there's not much hope for them to find a problem.Could have the fuel filter changed and check for sticking brake caliphers(have been known to stick on a KJ).I'd start there after seeing if changing gas stations doesn't work,though I would wait till the warmer months.Also certain positions on the '07's HVAC controller turn on the A/C system which will drop your mpg's(defrost and floor settings),that can be a factor also.

Oh and if your KJ was a former rental you may be just out of luck,poeple beat rentals do death so 15,000miles on a rental is like 100,000miles of normal driving.

 

[Vtolds]

I have a 2003 with 61,000 miles and I got 19 in the warmer months and I am currently getting 13 to 14 mpg.

 

[LibertyOrDeath]

Try driving like a grandma, it should increase MPG by 21.7%.

 

[J-Thompson]

I know this probably does not help
but we have an '03 lifted ,245/75 MTR's
we get 14+ in the flat swamps of south Louisiana all city
and can get 20+ all highway

I would have it checked out under warranty
heck that is what they are for
sounds to me like there is a problem but I have no clue what it could be
and just to "rub salt in the wound" I get better MPG in my lifted locked
I-6 3 speed auto TJ 14-16+ highway and close to the same city ,no OD

 

[nchorselover55]

What size tire do you have on your Liberty? Have you compared you speedometer reading against a GPS? Or, the odometer reading against milemarkers?

If someone put a larger diameter tire on you Liberty, you are going further than the odometer is showing. therefore, when you fill up... you actually have gone futher and are actually getting better fuel mileage.

Just a thought.

 

[vaughan1966]

I bought an 05', 29,000 miles on the ODO. I was getting 12-14 MPG.

Then I found this site !!! its good for 1 or 2 more MPG!! j/k


Heres what I did. Change the spark plugs first off ! This helped my MPG greatly. now I'm getting 15 city, but 19-20 highway. My libby wasn't a rental and you should have seen the plug after 29000 miles! My goosebumps were bigger than the electrodes on the plugs !!!
( could have used a different example but you know this is a family site )

hope this helps

 

[Kevin]

My current weighted average is 14.83MPG. Its probably more like 15 since I had a few fill-ups that were topped off. My car is still pretty brand new so I hope it may improve.

 

[Dave]

I do not know what part of the country you are in or what driving style you have but here it is cold. My gas mileage is the worst it's ever been right now. We have winter blend gas (10% ethanol per pump labels) These add up to worse gas mileage than warmer months. I am due for a plug change. As soon as Spring is here I will change them. It's too cold now and I don't feel like doing it in the cold. You should consider the same.

Right now use branded gas - run some injector cleaner through it (Chevron with Techron is real good) - keep your tires aired up to the proper pressure - Change your air filter - pcv valve. When the weather breaks, do a plug change, oil and filter change using synthetic. Mpg will improve as the weather gets better. The best you could hope for is 17-18 city and maybe 19-21 highway on an average. It is possible to do a little better or worse depending on mods, driveing style, terrain, etc etc.

Dave

 

[mckim]

i suck in math but let me try....
i filled my tank and got 330 miles before the empty tank warning went off.
i think the tank on average holds 20gal, so i'm looking at 16.5mpg, which is ok i guess, considering i commute 50miles to work each way with a combination of half city, half hwy

 

[VTNomad]

MPG's

My 2004 average 16.7 around town and 22.1 on the highway. I have noticed gas containing ethanol hurts my MPG's. It's impossible to find gas with less than 10% ethanol, some places sell 15% or 20%. If I use 10% ethanol, I lose 10% MPG.

Different years have differnt tank sizes. 2002-2003: 18.5 gallons; 2004: 19.5 gallons; 2005-2007 20.5 gallons.

Are you carrying anything on top that would create drag? Are you constantly driving into a headwind? Are you carrying a lot of weight, you lose 2% fuel economy for every 100 pounds.

http://www.fueleconomy.gov/feg/driveHabits.shtml

 

[2007Sport]

I bought a 2007 Liberty rental last October. It had 18,220 miles on it when I bought it. I was happy to get if for $16K and consider myself lucky to get a great value.

Anyway, I am tracking my mileage via an Excel Spreadsheet. I have installed new spark plugs (link http://www.autotrucktoys.com/liberty/E3-Jeep-Liberty-Diamond-Fire-Spark-Plugs-02-05-P23182C6756.aspx) and a K&N air intake. I just took a trip from Illinois to Nevada and back over 3600 miles. The difference in mileage I attribute to brands of gas with the Navajo Indian, gas station giving me (Armgen? brand) the best mileage of over 22 mpg.

So after 7500 miles I average 18.5 mpg. Compared to your mileage I guess I should be happy.



Date Gallons Odometer Miles Driven MPG
10/5/2007 8.649 18220 0.00
10/14/2007 15.781 18500 280 17.74
10/20/2007 19.007 18927 427 22.47
10/28/2007 16.43 19115 188 11.44
11/18/2007 15.958 19407 292 18.30
12/10/2007 18.804 19731 324 17.23
12/15/2007 16.542 20100 369 22.31
12/18/2007 18.622 20465 365 19.60
12/24/2007 14.735 20770 305 20.70
12/30/2007 17.002 21099 329 19.35
1/11/2008 10.777 21287 188 17.44
1/22/2008 14.729 21544 257 17.45 New Plugs installed
2/7/2008 25.373 22016 472 18.60 New Air Intake installed
2/12/2008 13.973 22238 222 15.89
2/20/2008 7.684 22365 127 16.53
2/20/2008 17.968 22751 386 21.48
2/21/2008 18.898 23103 352 18.63
2/21/2008 18.658 23476 373 19.99
2/21/2008 17.62 23804 328 18.62
2/22/2008 13.816 24111 307 22.22
3/2/2008 18.599 24485 374 20.11
3/2/2008 18.589 24887 402 21.63
3/3/2008 15.279 25167 280 18.33
3/3/2008 18.69 25513 346 18.51
3/3/2008 15.541 25792 279 17.95
3/4/2008 9.751 25945 153 15.69
417.47 7725 18.50

 

[Ktmguy23]

I appreciate all of the responses. I would be more than happy if I was getting what 2007sport is getting with his. I think my next move will be to check one of the easy to get to plugs and just see what I am working with.

 

[BNJ-KJ]

When I got mine I was getting around 18 mpg highway(that's about all I drive). I changed the plugs and put in a k&n filter and I'm up to 22 mpg now. That's with granny driving though.

 

[Ktmguy23]

Well, I went ahead and changed the plugs today. I went with Autolite Plat 2's. The plugs that came out were not that bad but I wanted to rule this out. I would say they oe plugs had about a .05-.055 gap. I put the new ones at
.040. Hopefully this helps.

 

[LibertyOrDeath]

I've been seeing ads for these Pulstar Pulse Plugs. Anybody know if they live up to their claims? Up to 1,000,000 watts of peak power from a spark plug sounds good but seems like a load of crap.