TJ 4.0 Gas mileage

Deerhunter30 · #1 (**permalink**) 07-29-2004, 12:13 PM

I plan on buying a Rubicon when my wife graduates from nursing school in ten months. I know the window sticker states that they get 16mpg city and 19mpg hwy. Does anyone with a 4.0 TJ know what gas mileage they are getting from their Jeep?

jeepmaster · #2 (**permalink**) 07-29-2004, 02:10 PM

ive got a 4.0 XJ that gets about 220-240 per 20 gallon tank depending on how far past e im willing to drive it. not sure if that helps, but you should be able to expect at least that. i believe thats 12 MPG, the sticker is gonna advertise the MAX amount. like full to bone dry. if i run it from full to just E and fill it up, it will only take 16 gallons, meaning ive still got 4 in reserve should i choose to dance w. fate

phatyaspen · #3 (**permalink**) 07-29-2004, 03:07 PM

i run 4.88s w/ an auto and 33"s i get about 12-3 when i drive reasonable hope that help

Deerhunter30 · #4 (**permalink**) 07-29-2004, 03:08 PM

Jeepmaster,
If you get 220 to 240 miles per fill up....and each fill up is approximately 16 gallons....that equals between 13.75 and 15.0 mpg. I currently get 14.0 in the city in my 83 CJ7. I was hoping that that would improve with a new Jeep.

laneiac · #5 (**permalink**) 07-29-2004, 03:14 PM

I wouldnt expect too much better. The best i have ever gotten in my 4.0 YJ was 17.5, driving very conservatively.

redrooster · #6 (**permalink**) 07-29-2004, 03:34 PM

Just go get a Kia and chop the roof off. I hear they get great milage.
Seriously, Jeeps get crappy gas mileage. If you really want one then ignore that window sticker guesstimate.

jay79cj7 · #7 (**permalink**) 07-30-2004, 12:17 AM

I have a 4.0 XJ, auto with stock tires and 3.55 gears. I consistently get 16.5 mpg, but sometimes a mile or two higher depending on how much highway driving I do.

Deerhunter-
Off topic, but how much lift did you use to clear those 32's? I am going to build up my CJ this winter, or at least thats the plan... 32 is about what I am thinking for tire size.

graewulf · #8 (**permalink**) 07-30-2004, 07:26 AM

Alot of gas mileage depends on your driving style and whether it is stick or auto... stick will get a little better if you know how to drive it, and if you are easy on the skinny pedal, use the cruise control alot, and drive highway mileage you can see 19 on the highway (of cours average will be more like 17). my GC gets nearly 19 on the highweay with the 4.0 and 30's on it. but around town I see closer to 16.

Junkpile · #9 (**permalink**) 07-30-2004, 07:59 AM

We've averaged 15.7 mpg in our 02 4.0 WJ since it was new.

Deerhunter, DO you clear those 32s? Those are factory springs right? I like that you used the Holley 350, most jeepers overlook that one. It's a natural match for the upgrades that most people eventually do to the 258. Headers, intake, mild cam....

Deerhunter30 · #10 (**permalink**) 07-30-2004, 08:29 AM

jay79cj7,
I don't have any lift on my jeep. I do rub the fender flares in flex situations. In fact the fender flares have been "naturally trimmed" by the tires. I did not put these tires on the Jeep. They were on it when I bought it. Without a lift the largest that I would have put on it would have been 31s. I wanted to lift the Jeep up about 3" to get better clearance, but that has not happened yet. Between replacing the junk Carter that was on it, to exploding the rear differential, to having to replace the stripped axles with one-piece axles, to having to put a 3 core radiator to keep it cool with the AC on, to replacing the battery & alternator......I have not had enough money for a lift. My current plans are to buy a Rubicon in ten months when my wife gets out of nursing school so I cannot justify lifting it at this time.

Junkpile.
As stated above, there are times that I do not clear the 32s and yes those are factory springs. I like the Holley 350. I used to have a drag car when I was younger and had experience working on Holley carbs so I decided to go with that. They are so easy to tune. I have an air/fuel meter installed and I used that to set the jets. I kept putting different jets in until I got what I wanted. I have also changed out the power valve because the one that came in it would open up when cruising at highway speeds. With the old Carter carb I got around 11 or 12 mpg in the city. Now I average between 13.7 and 14.4 mpg. in the city. There is no comparison to how it idles either. It's like a whole new motor.

southtj · #11 (**permalink**) 07-30-2004, 09:32 AM

I've got an 04 with the 3.73 rear and 31" tires. I average about 13-15 city and about 18 highway. I know that I could get a LITTLE better mileage if I took it easy on the skinny pedal but that's just the way I drive. My wife was hoping for better mileage when we bought a 6cyl vehicle but I knew it would be a gas hog. I still love it.

jeepmaster · #12 (**permalink**) 07-30-2004, 10:27 AM

yea i guess i was just calculating it off the total tank size.. i liike the results of your way much better. side note on my mileage - my jeep has intake and exhaust and sounds really nice around 3K plus im a teen and like to hear it roar so my mileage will generally be lower than what you'll get

XJNick · #13 (**permalink**) 07-30-2004, 11:02 PM

Hi,

I usually get right around 19.5 MPG in my Wrangler with AX-15 transmission (I usually shift at 2000-2200 RPMs). Oh and It has the stock gearing.

-Nick

whiterubicon · #14 (**permalink**) 07-31-2004, 11:43 PM

My 04 rubicon get an average of 15 mpg with a stick and the a/c on all the time. The best I have ever got was 18 mpg but that dont happen often. a few times I have seen it as low as 13mpg. I check the mileage every time I fill it up.