I notice you're running 31" tires, have you done anything to correct your speedometer to compensate for the taller tires? Do you have a GPS? If so, compare the speed indicated on your GPS with your speedometer at around 45 to 50 mph and see if it's off. Mine is almost dead on with the 30" tires, so I suspect yours may be slightly off. This will affect your gas mileage calculations, but not by 5 mpg (the difference between your mileage and mine). I know you can get replacement speedometer cable gear that will correct for taller tires, but most folks don't do it unless they go 32" or taller. I'd also try upping the air in your tires by 5-8 psi and see if that helps. What gears are you running? I have no idea what I have, but I'm assuming they were the stock gears for the non-tow package X. The tow hitch on my TJ is an aftermarket bolt on.
mileage
- Thread starter superj
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I notice you're running 31" tires, have you done anything to correct your speedometer to compensate for the taller tires? Do you have a GPS? If so, compare the speed indicated on your GPS with your speedometer at around 45 to 50 mph and see if it's off. Mine is almost dead on with the 30" tires, so I suspect yours may be slightly off. This will affect your gas mileage calculations, but not by 5 mpg (the difference between your mileage and mine). I know you can get replacement speedometer cable gear that will correct for taller tires, but most folks don't do it unless they go 32" or taller. I'd also try upping the air in your tires by 5-8 psi and see if that helps. What gears are you running? I have no idea what I have, but I'm assuming they were the stock gears for the non-tow package X. The tow hitch on my TJ is an aftermarket bolt on.
superj
Active member
i got in the habit of checking the speeds with a gps in my bmws because i was always doing stuff to them so the speedometer was always wrong. i had to learn to convert kilometers to miles because i had a euro cluster in my 89 for a long time and my dad had a real euro 635csi so everything was in german in that one. i didn;t know what the words on the hvac panel or some of the other panels said. i knew what wasser was, and that was pretty much it
Other than the year of our Jeeps, they seem to be set up pretty much the same. I know mine has fuel injection and electronic ignition and assume you have the carburetor and distributor. When was the last time it had a tune-up and carb adjustment? Seems you should be getting better mileage than you're getting...
superj
Active member
i just put another carb on about 4 months ago because the weber was having trouble and i didn;t like it.
i have to do a different style distributor though because this one is set up for the ecu to do whatever it did before the nutter by pass was done and then the carb was swapped (the original carb).
i think mine should get better also because my wife's 93 was set up just like ours but was fuel injected and got mid to high teens in town and 20-21 on the highway.
i have to do a different style distributor though because this one is set up for the ecu to do whatever it did before the nutter by pass was done and then the carb was swapped (the original carb).
i think mine should get better also because my wife's 93 was set up just like ours but was fuel injected and got mid to high teens in town and 20-21 on the highway.
superj
Active member
i think part of hte reason this one gets such bad gas mileage is someone did some motor swapping on it. the block is a 99 4.0, who knows what is on the inside, and the head is the 87 4.2 head. i don;t know if its set up like a stroker or what but this jeep will smoke the tires from a standing stop if you floor it and it does a hundred on the highway easily
clydethepirate
New member
I actually get 22 MPG on average but everything is stock. I'm expecting it to drop with larger tires.
In the mid 70's when Opec was cutting off foreign oil supply, the U.S. Government done a test and determined for a normal vehicle 55 was the most economical speed for the highway.. thats why we have the 55 mile speed limit. Of course its 70 now on interstate in Arkansas, and 75 on the turnpike. Guess your paying to go 5 mph faster....LOL
My Jeep will do 75 but its not real comfortable.....:MDB2:
In the mid 70's when Opec was cutting off foreign oil supply, the U.S. Government done a test and determined for a normal vehicle 55 was the most economical speed for the highway.. thats why we have the 55 mile speed limit. Of course its 70 now on interstate in Arkansas, and 75 on the turnpike. Guess your paying to go 5 mph faster....LOL
My Jeep will do 75 but its not real comfortable.....:MDB2:
clydethepirate
New member
In a normal 2 lane highway your lucky to get over 45 here....... lots of eldery
The 88 Cherokee I had would do the same. It had a Jasper engine in it and was real strong, you could stomp it from a stand still and smoke would roll as it turned sideways. This is where I developed a respect for the Jeep strait six. The tag on the radiator support said it was a 4.2. I know when I traded it the guy drove it and said he had never seen a six that strong.
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