Terrible MPG
#1
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Year: 1999
Model: Cherokee
Engine: Straight 6 4.0
Terrible MPG
Okay, I’m not here to complain about bad mpg bc it’s a lifted Jeep. When I lifted it I knew I was gonna get bad gas mileage. I have an issue though. Last week I was getting about 10-13 mpg like I normally get. This week I am getting 3-4 mpg. I don’t think that has to do with lifting it and big tires. I have only got 40 miles to a tank. The tank is 15-16 gallons and my 99 check has a straight six. Any thoughts on what went drastically wrong?
#4
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Year: 1999
Model: Cherokee
Engine: Straight 6 4.0
I don’t know how to delete a post. But I’m sorry this is a dumb question. I’m young and have no clue what I’m doing. Just trying to learn. I know my calculations might be a little off but they aren’t too far off. I’m sorry for wasting time. 🤙🏼
#7
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Year: My Jeep is a GMC
You sure no one is stealing your fuel?
Apply a very thin strip of scotch tape spanning the gap on the fuel door that way you can see if its been tampered with, trail cam works too.
Apply a very thin strip of scotch tape spanning the gap on the fuel door that way you can see if its been tampered with, trail cam works too.
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#8
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Okay, I’m not here to complain about bad mpg bc it’s a lifted Jeep. When I lifted it I knew I was gonna get bad gas mileage. I have an issue though. Last week I was getting about 10-13 mpg like I normally get. This week I am getting 3-4 mpg. I don’t think that has to do with lifting it and big tires. I have only got 40 miles to a tank. The tank is 15-16 gallons and my 99 check has a straight six. Any thoughts on what went drastically wrong?
No tank leaks? With the engine running, inspect the line noted above from the fuel tank to the fuel rail for any leaks while under pressure from your energized fuel pump.
I believe your accounting of your lost MPG but that kind of loss is usually associated with an easily detected leak or, as mentioned by another poster, theft. A locking gas cap or other theft counter-measure seems in order if you have no leaks.
#10
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Year: 1995 RHD
Model: Cherokee (XJ)
Engine: 4.0l
I don't think this would relate as incorrect mixtures to those extremes should cause running issues/none running at all but I also had mine run at 3-4mpg. The difference for me was this was on LPG and not Petrol. My issue was one of the wires from the Lambda sensor was snapped. My best guess was my LPG system was unable to work out its air/fuel ratio so was over fueling a lot. Although I wouldn't dismiss it, I do doubt that if it were using 2x or more fuel than required, it would run without issue.
#11
CF Veteran
First thing for me - brim the tank, zero the trip and run till the fuel light comes on. Brim the tank again and note how much fuel it takes as well as how far you've gone.
This is an accurate measure of fuel mileage.
This is an accurate measure of fuel mileage.
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