Gas Mileage Tips or Tricks?

Greaser · **Posted:** Thu Apr 29, 2010 7:38 pm

Awesome tips, thanks everyone, I just joined fuelly.com so I am gonna start tracking it and try to have some better driving habits.

Neatus · **Posted:** Fri Apr 30, 2010 8:10 pm

I am getting about 15 with my SFA....I keep the KJ as light as possible and I am a slow slow slow driver.

SavageUrge · **Posted:** Fri Apr 30, 2010 8:39 pm

This may sound strange, but after replacing my stock airbox, it seems my mileage is taking a jump. Driving conservatively (read: Like a grandma), I got 18.6 actual (19.3 according to the EVIC) mpg with the K$N installed. All day today I've been driving like a maniac doing mostly city with a little highway thrown in and I'm still at 19.3 by the EVIC (yes, I reset it every fill up). Driving like an a-hole with the K$N would get me around 17.7 by the EVIC. The stupid thing is, I'm using the factory original 7 year old filter that came with the Jeep. I barely used it before I put the FIPK on. I can't wait til my Amsoil get's here to see how much it opens up!

LibertyFever · **Posted:** Sat May 01, 2010 5:35 pm

Okay I'll throw my two cents into this conversation.

To improve your gas mileage I'm going to suggest some common sense ideas like reducing the amount of extra weight in your vehicle, remove any roof baskets & lights from your roof and drive like you have an egg beneath your foot (no hard acceleration or braking). Also keep your vehicle tuned up. I've heard that using Mobil 1 synthetic oil helps gas mileage.

I calculate my gas mileage from how much gas I fill up with and from the miles driven from my odometer and we all know how accurate the gas pumps and our odometers are.

Once upon a time I had a roof basket c/w four Hella500 lamps and a spare tire on my roof. My gas mileage dropped so I've removed the roof basket and moved the lights to the bumper.

Sure it is a Liberty not a Prius so one can't expect great gas mileage. From my calculations I'm averaging 19 to 20 MPG.

HoosierJeeper · **Joined:** Sun Feb 15, 2009 8:23 am **Posts:** 1218

Get rid of the Jeep...I've never been above 20 MPG on the highway.... :pepper:

Dje Ryu · **Posted:** Mon May 03, 2010 1:28 am

Just got back from a 2200 mile trip. Total amount of gas used was 100.5 gallons. Changed the oil and filter, PCV valve and filter, and the air filter before I left. I have been using Mobil1 oil for the last 8 oil changes (about 4000 miles between each change). Need new plugs though I think. I've been feeling a slight vibration at idle, lately.

As a lot of others have already mentioned, I pulled a bunch of weight from my KJ before I left, as well. All four skids and the rear hitch came off. I also took about 150 pounds of stuff out of the inside, right down to the floor mats. The only things I didn't take off were the Detours' Backbone and RL's Step Skinks. They hold too much plastic in place now. I may go ahead and take them off before I make the trip again in August, just to see if I can squeeze out another mpg but, my Jeep will look funny with no front bumper or all the trim. Probably be even less aerodynamic, too.

corwyyn · **Posted:** Mon May 03, 2010 4:15 am

Prior to my lift and larger tires I had replaced the Goodyears with some Yokohama 235/70s which were around the same diameter as the stock tires. On one particular trip of approx. 450 miles I stayed in the 65-70mph range on the freeway using cruise as much as possible and I was able to average almost 25mpg (something like 24.7 IIRC). I had my Garmin V with me and the difference between the odometer in the Jeep and the GPS was about 0.3 miles over a 100 mile span so I know the odometer was pretty accurate.

Now with my lift and tires I am still able to get around 19-20 on the highway, less in the city but still not bad. I find mostly it boils down to good maintenance and having a light touch on the skinny pedal.

ihatemybike · **Posted:** Mon May 03, 2010 2:24 pm

On the way back from SMORR we managed to get a 21.7 mpg tank out of Eugene. Only thing done was drafting semis with box trailers, always picking up a faster truck as we got passed. As Jayme has stated before this is done 2.5-3 seconds back. At 65 mph this is between 235-285 feet (or 15-19 car lengths) back which is more than enough distance should the truck slam on its brakes.

Mythbusters screwed their drafting test up by starting at 100 feet (6 car lengths) and moving closer. They never tried moving further back, which is a shame cause a truck's wake is huge! I have logged over 10k miles using the 2.5-3 second method and average 20% over EPA ratings.

jnaut · **Posted:** Mon May 03, 2010 2:52 pm

I had slightly over 20 mpg on a long highway trip loaded with kids and camping equipment. My in-town mileage hovers between 14.5 and 16mpg. Unfortunately due to my job a take a lot of short trips which, in the Jeep, is a major mileage killer. I'm pretty confident my Jeep will hover right in the EPA estimate of 17/21 if it weren't for my short trips where the temp gauge doesn't even get up to full operating range.

For you guys talkin' about weight:

Rule of thumb: 1/4mpg for every 100lbs.

JeepinJarhead03 · **Posted:** Mon May 03, 2010 3:07 pm

I avg about 17 with all of my stuff intact and loaded, my mpg went up an avg of 1.5 mpg immediately after putting on a 160 lb front bumper

Pretty sure I'm sitting on the bottom threshold of what the mpg's for my particular engine build, gearing and tire combo will get in moderate driving conditions, without taking stuff out, or off, or swapping tires, it's not going to get better than 17 mpg below 60ish mph, at 70-80 it gets 15.5 - 16 mpg

LibertyFever · **Posted:** Mon May 03, 2010 5:31 pm

Ever since I bought my Liberty I've kept track of the gas mileage so today I thought I'd look back at just how good my gas mileage was way back then.

July 2006; a bone stock 2004 Liberty Sport with absolutely no skidplates, towhooks, lights, lift kits, roof baskets on P205/75R16 all season tires: 22 MPG

it really hasn't dropped all that much... now I typically get about 19 to 20 MPG

BVCRD · **Posted:** Tue May 04, 2010 12:18 pm

yellocoyote wrote:

I topped off the tank this morning after the 2nd half of the trip home drafting semi trucks... and was at 20.8mpg. It's definitely doable.

I was drafting a semi once headed up I-76 out of Denver. Sucka slammed on the brakes. I swerved to miss him, going into the fast lane and there was a mess of road gators strung all over the road. Haven't done it since.

ihatemybike · **Posted:** Tue May 04, 2010 12:37 pm

BVCRD wrote:

yellocoyote wrote:

I topped off the tank this morning after the 2nd half of the trip home drafting semi trucks... and was at 20.8mpg. It's definitely doable.

I was drafting a semi once headed up I-76 out of Denver. Sucka slammed on the brakes. I swerved to miss him, going into the fast lane and there was a mess of road gators strung all over the road. Haven't done it since.

The fact that you had to swerve tells me that you were too close and thus doing it wrong, see my post above Jayme's.

L.O. · **Posted:** Sun May 09, 2010 2:37 am

I get 21mpg in mixed city/highway (mostly highway). I keep the KJ tuned up, tires aired up and use my cruise as much as possible. I never knew you could get a draft effect from trucks that far back.....I'll give it a try.

SurfGuitar141 · **Posted:** Sun May 09, 2010 9:41 am

After purchasing my 2005 Renegade new...(Oct, '05).... I went right to Mobile 1 synthetic oil, and replaced the stock air filter with a K&N that fits in the stock air box. I just recently replaced the stock muffler with a Thrush high performance universal fit muffler releaving back pressure...(haven't had this latest mod long enough to see it's benefits yet)
Today I plan to replace the factory spark plugs, not sure what new plugs I will get, but they will be better than the originals.....(Bosch Platinum, or NGK Platinum most likely)

I understand the reasoning many mention here about reducing weight, but I don't go anywhere without my spare tire....(been screwed twice doing that).....my roof rack serves a purpose, as does the fishing rod rack on the front bumper, so they're not going anywhere, with that said I don't do a lot of highway traveling in my Liberty, and weight reduction wouldn't matter a whole lot for my situation, if I had to do a long distance commute everyday I would think differently, but I have an 8 mile commute to my main job, and a 1.5 mile commute to my second part time job, other than that my KJ takes me fishing, surfing, or to the shooting range that's only 8 miles from my front door.

I think it all boils down to what one contributor posted here already......It's a Jeep !

curt7088 · **Posted:** Mon May 10, 2010 10:51 am

As was said earlier about tire pressure... you should always keep your tire pressure at eh optimal operating level for your vehicle, not what the tire says, for safety.(when on the road) What good is it going to be when you have 60 lbs of pressure in your load range E tires because it says that is the highest pressure allowed by them when you stop?? all it will do is make your vehicle more prone to sliding and causing the ABS to engage earlier although we shouldn't have load range E tires on our vehicles, some tires in the sizes you want can only be found in something like that. and if your vehicle recommends a higher tire pressure than the maximum pressure your tires are recommended for then get new tires because their load range is too low for your vehicle to begin with.

ISpy · **Posted:** Sat May 15, 2010 8:28 pm

I've only ever found two secrets to getting better gas mileage in a Jeep Liberty 3.7...

#1. In the morning before you get on the freeway to drive to work, stop at a McDonalds and eat a greasy egg McMuffin breakfast. Before leaving the parking lot, open the hood and let out all those greasy combustable farts into the air intake. This will improve your gas mileage by at least 5% depending on the amount of farts you can expel into the air intake. Note; to save time, after eating, go directly to drive and put the A/C on recirculate while farting on the drive to work. This is a less effective method but is helpful on time reduction in the case of being late for work.

#2. Never drive over 30 mph.

tommudd · **Posted:** Sat May 15, 2010 10:59 pm

Fully loaded with tools , rack, lights on top, tools in back, ARB bumper, rock rails, Kilby skid all heavy stuff
You can see the corrected speed on the GPS and the RPM/ Miles per gallon average on the scan gauge. Pretty much what I average around here

MonsieurGlen · **Posted:** Wed Jun 02, 2010 3:49 pm

I was very concerned about my mileage so I paid close attention to how I was driving and tracked it for about 2 months. I started off between 14.6 and 15.4 mpg the first few tanks. I put in E3 diamond fire plugs and saw an increase to about 16.3 mpg. I never saw much of a consistent increase for the next few weeks, got frustrated and said forget it. While not paying attention to my mileage or driving habits, I looked at my EVIC and have now been between 17.4 and 17.8 mpg consistently.

My advice is to not worry about it and you will be fine. :2cents:

LibertyCRD · **Posted:** Wed Jun 02, 2010 8:14 pm

After extensive testing over the past several years with multiple Chrysler 4x4s, here are the things that will actually help your mileage:

Tires. MTs will kill mileage. ATs can be bad too depending on tread pattern. If you really care about mileage, stick with HT tires. Weight of the tire will kill mileage too. Try to stick with tires that are as close to stock weight as possible. Height of tires will kill mileage by increasing the leverage needed to start and accelerate if you go taller. Try to stay somewhat close to stock height. Keep the air pressure up to the proper level will decrease rolling resistance. Tires are a HUGE factor in mileage.

Engine load. Is your A/C on? Do you have a clutch driven fan? Is your air filter clogged? All these things increase load on the engine. Try ditching the fan and installing an electric fan. Around town and on 55 MPH highways, roll the windows down and turn the A/C off. I learned that anything you can do to decrease load on the engine will improve mileage.

Driving style. Accelerating very slowly, maintaining lockup in overdrive, and sticking strictly to the speed limit will make the biggest difference. Anticipate red lights so you don't have to make a complete stop. Drive easy on the throttle and the brake. I've seen 15-20% improvement in mileage just from driving style alone!

Things that have NOT increased mileage in all my testing: exhaust systems, "cold air" intakes, not carrying a spare, using synthetic oils, etc. These things are hyped and I could never verify any gains with them in the real world.

Gas Mileage Tips or Tricks?

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