I feel like this MPG gauge requires a PhD...

rubi_vette

Member
I am about 3 months into ownership of my JLU. I daily drive my Jeep, so I usually drive about 500 miles a week. How does the MPG Gauge even work? I went on a trip to the other side of town (15 miles) and it says "97" miles remaining, by the time I got home, it only says "90" miles remaining. I am trying to figure out when does the light for low fuel come on. I read that some people go by the fuel guage, others just never let the car go below half. Lol. IMG_5457.jpg
 

OverlanderJK

Resident Smartass
It has to do with how you are driving and you current fuel economy and your total fuel economy. It’s not accurate, never has been and I don’t think any claims it ever is or was.
 

wayoflife

Administrator
Staff member
Not 100% sure what the confusion is coming from but your range and average change based on how fast or slow or how much work your engine is doing.
 

rubi_vette

Member
Is there a way of truely knowing how much gas I got left, or is it a FIXED number at when the light comes on? Like in my other cars it was 60 miles left till E, than the light comes on
 

OverlanderJK

Resident Smartass
Is there a way of truely knowing how much gas I got left, or is it a FIXED number at when the light comes on? Like in my other cars it was 60 miles left till E, than the light comes on
It’s 50 but wouldn’t it just be easier to stop at a gas station? Seems like you like to make things a lot harder than they need to be. Do you wait until your pantry and refrigerator are completely out of food before you go shopping or do you do it before you run out?
 

rubi_vette

Member
It’s 50 but wouldn’t it just be easier to stop at a gas station? Seems like you like to make things a lot harder than they need to be. Do you wait until your pantry and refrigerator are completely out of food before you go shopping or do you do it before you run out?
Yeah, I do actually regarding my food. And Good to know at 50.
 

wayoflife

Administrator
Staff member
From experience and from number crunching using a calculator, I have always found that the light comes on when you have about 4 gallons of gas left. That said, the actual range you have will be determined by a lot of different factors and the biggest of which is, how fast you're driving and/or how much your engine has to work. Typically, worst case scenario is that you're only getting about 10 mpg so that would be about a 40-50 mile range.
 

kevman65

Hooked
First, your fuel mileage is going to vary because of driving habits. Idling time, mashing the skinny peddle, stop and go driving.

Second, miles left is an ESTIMATE based on your driving habits the brain box has learned over time and amount of fuel left in tank.

Third, your fuel gauge is on the conservative side, it will read less than you actually have in tank.

And D, the 50 miles left thing or gallons left doesn't hold true on the low gas light. I've had the light come on as late as 20 miles left or under 2 gallons of gas based on how much I could get into the tank. Yes, I've been able to put 20 gallons into the tank, ONCE.

For me, I try to fuel up when I hit 1/4 tank left, no surprises that way.
 
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cozdude

Guy with a Red 2-Door
As mentioned it’s just a rough calculation based on driving habits and current conditions. don’t over think it. Just fill up when you can and don’t run it dry.

I personally put about 10-15 miles on the Jeep daily. My avg mpg is 12. That is based on the idle time warming up in the morning plus driving. My light comes on around 40 miles left which is normally around 1/8th of a tank left.
 
For me it is always important to have enough gas to make it to the next gas station. In fact my golden rule is to have enough gas to make it back to where I last successfully got gas. Some gas stations are on their last leg and are barely operational, or you find out there is no gas! Or the credit card system (or card) does not work and you are short of cash. Due to the fear of being stranded in a very remote area (e.g. Trinity atomic bomb test site), I rarely let my tank get less than half empty!

If none of this applies to you, then I am not sure why you are worried about it. 😀
 

AZDIESELPIG

Member
I am about 3 months into ownership of my JLU. I daily drive my Jeep, so I usually drive about 500 miles a week. How does the MPG Gauge even work? I went on a trip to the other side of town (15 miles) and it says "97" miles remaining, by the time I got home, it only says "90" miles remaining. I am trying to figure out when does the light for low fuel come on. I read that some people go by the fuel guage, others just never let the car go below half. Lol. View attachment 385724

I would be filling up at that level of remaining fuel REGARDLESS of what the pretty display with lights tells me. Not only will it ensure you will not run out of fuel but your fill up will cost you less than if your in the red.

I always laugh when my Dodge APP would let me me know I had less than 1/8 fuel in my ScatPack and JLU - yes Dodge I know I can read a gauge.
 
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