My LJ is a pig on fuel. This can't be real life.

I've just never been one to worry about fuel mileage. I'm on my 6th jeep and they were all around 14 mph no matter how I drove. I've owned two 6.7 Rams and now my first 5.7 Hemi. I've always just wanted to drive the vehicle that I wanted and fuel mileage was just never in the equation.
 
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DavidBT said:
I've just never been one to worry about fuel mileage. I'm on my 6th jeep and they were all around 14 mph no matter how I drove. I've owned two 6.7 Rams and now my first 5.7 Hemi. I've always just wanted to drive the vehicle that I wanted and fuel mileage was just never in the equation.
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Yup.
 
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My LJ on 33’s (3.73, NSG370) gets around 15mpg. Range anxiety on remote mountain roads starts around 150 on the odometer, around 200 on the highway.

I was shocked last week to see my YJ (4.0, 30’s, 3.55, AX-15) get nearly 17mpg. I got nearly 300 miles on that tank (and was pretty sure I was going to run out of gas on the way to work).

It is what it is.
 
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My 06 TJRU 6sp with 32s and stock 4.10 and 2.5” lift gets 14ish Hwy and 11ish on the trail. Trail is lower because even though I’m going slower I tend to keep the revs up. For reference my 19 F250 6.2 gets 8.6 city and 15 Hwy. You are driving a vehicle with the aerodynamics of a cement block.
 
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I have a 19 gallon tank and at 15 MPG that’s a range of 285 miles. That got me through three days of off-roading along el Camino del Diablo with fuel to spare, and I go two weeks between fillups driving to work.
 
Didn't the 05 and 06 computers have a defect? Wonder if that's been addressed.

I just did a head gasket on an 04 WJ and the four O2 sensors and the herd of cats is nuts.

My 97's mileage drops every time I wiggle the exhaust loose. You might have a cracked header or bad cats.

I also think everyone's speedo accuracy is all over the place... so you've just got to take mileage claims with a grain of salt.

I typically get 12 to 13 and 9ish wheeling. It's been in the 9s lately and down hard on power so I suspect my cat is clogged and my fuel pressure is around 35 psi.

-Mac
 
macleanflood said:
Didn't the 05 and 06 computers have a defect? Wonder if that's been addressed.
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Issues definitely can come up but if it runs/shifts well with no codes I wouldn’t point to the PCM as a problem.

Do you know your engine compression numbers @freebo86 ?

macleanflood said:
I also think everyone's speedo accuracy is all over the place... so you've just got to take mileage claims with a grain of salt.
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My speedometer is accurate using a speedo healer, and I check my MPGs every fill.

macleanflood said:
I typically get 12 to 13 and 9ish wheeling. It's been in the 9s lately and down hard on power so I suspect my cat is clogged and my fuel pressure is around 35 psi.
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Do you struggle going around 50mph+ that’s how my rig was with a clogged pre-cat. Hopefully you solve the issue without too much grief.
 
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The only mpg calculations that can be trusted are consistent, tank over tank calculations with miles/gallons to fill. Individual tanks can swing wide from one to the next because of inconsistency in pump shutoff triggers, the 05-06 burp issue, etc.

I enter every fill-up into an app on my phone which loads to a website and does those calculations for me. Over two years I've averaged 12.3 mpg, but I'm not sure I've ever had a single tank that was 12.3 so I wouldn't know otherwise. I see everything from 11 to 13.5 on regular driving. If I'm coming out of the mountains I'll have a tank at 16-17, and if I'm wheeling in 4 low I'll get around 9.

This is with 35s, AX15, 4.88 in an LJ.
 
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KennethS said:
I do. Bought mine from the original owner when it was almost 4 years old. Still get around the same mileage. 15-ish in town with the AC on and close to 18 all highway miles.

I was completely amazed on a weekend off-road trip around 2010. Steady 35 MPH on forest roads and got 23 MPG out of two tanks. It’s amazing how much you lose from stop and go city driving.
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Yep, the stop and go gets you on one end and the aerodynamics on the other. The power (and therefore fuel) required to overcome drag increases with the cube of speed, so the amount of fuel burned to overcome drag at 80mph is about 1.8x that at 65. (It should not be inferred that 15mpg@65 would extrapolate to 8.3mpg at 80 because there is a proportion of consumption associated with loads that don't increase at the same proportion vs speed, such as rolling resistance and drivetrain losses).

I'm not sure of a passenger vehicle sold in the past 40 years that's likely to experience more drag than a TJ or earlier Wrangler.
 
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2003 Wrangler 4.0L 5speed

Driving 1200 miles home from Florida I got 15mpg highway in factory configuration. IIRC its rated for 17mpg highway, but I did 70-80mph. Big box wind drag, about right

Street tires, so Id imagine with a lift, heavier tires, expect worse. In todays world, its terrible MPG

Then again, we invaded Iraq the model year I have and oil prices surged high. So it wasnt good mpg for a daily driver then either

Not an ideal DD, more of a toy
 
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Apparition said:
I always plan on 200 miles per tank
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^^^^ Same here.

MPG is directly related to fun. If I want to have fun and shift at 3k-ish mpg will suffer. If I dawdle around I can get upwards of 16 mpg average

2000, 4.0, 5spd, 33's, 4.56's, 3" SL
It's my DD
Since I bought the TJ in 2021..
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IMG_6914.PNG
 
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TheBoogieman said:
I bought my wife a 04' WJ. Yesterday she said, "something must be wrong with my Jeep because it gets terrible gas mileage." I asked what it was getting and she replied, "I don't know, but $20 of gas doesn't last long." I told her someone new is in the White House now and gas prices have doubled. 🤫
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I ‘herd’, as from members of Cult 45, that Biden controls world oil and gas prices. Dark Brandon strikes again!
 
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