What's up with the variance in fuel range?!

[krazyboi]

True, but that's not what I meant. I meant that the fuel dispensers have a shut off when the tank is "full," but what the dispenser sees as "full" may be variable at different stations, and even with pumps at the same station.

It shouldn't that big of a difference, but it could affect the amount of fuel in the tank. The variance in range that you see on the screen probably has more to do with your average MPG as I stated before.

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[JIMBOX]

My jeep(3.6L) mileage/mpg operates exactly as my RAM 5.7L--the "MILES REMAINING" will change depending on your driving speed/gear and economy driving !

It just ain't etched in stone !

W.E.

JIMBO

 

[paulr]

If true, best answer here

Thank you!!

this is correct. the range is calculated on recent MPG so it will be higher or lower depending on how you have been driving recently

 

[Ma$$iveDebtAche]

Seems obvious to me that the range would vary according to the most recent MPG. Otherwise it wouldn't serve much purpose.

 

[Martindfletcher]

Also depends on jeep angle going downhill lowers the range in frightening ways when off-roading,

 

[ormandj]

If it hadn't been explained well enough yet, yes, a 20 gallon tank is a 20 gallon tank, but mpg is what drives the calculation to display how many miles you can drive on a single tank. Let's break this down.

1) If your vehicle gets 10 mpg on average, a 20 gallon tank will net you 200 miles, on average. Thus, the computer, on a full tank, would show you 200 miles if using the 10 mpg average.
2) If your vehicle gets 20 mpg on average, a 20 gallon tank will net you 400 miles, on average, and that is what would be displayed.

As your driving style/climate/etc have changed, so has your mpg. The reason everyone mentions mpg is the equation to calculate how many miles a tank will allow you to drive is inextricably linked to the tank volume and the distance you can drive per fixed unit (miles per gallon, in this example).

Additionally, adding another variable (every pump doesn't fill quite the same) probably accounts for a mile or two on a tank. Same for the position of your car, if you're on an incline it could increase or decrease the fuel level at the sensor, so a variance of 10-20 miles isn't uncommon at all, even if all the other factors (climate/driving style/load/passengers/etc) are all the same.

 

[sigsegv]

this is correct. the range is calculated on recent MPG so it will be higher or lower depending on how you have been driving recently

Yup, absolutely correct. I get crap mileage most of the time due to city driving and short trips. When I head out on the highway with a pretty full tank, my estimated range increases for 20-30 miles straight.

I haven't figured out how much history the computer uses for the estimation, but it's at least 20 miles or 30 minutes worth. No idea if it's temporal or distance.

 

[LLANERO]

Wow way over everyone's head here. I'm not talking about gas mileage...????!!

The computer multiplies the number of gallons in your tank by your average MPG for the past X number of miles to estimate the range. So, YES MPG has a lot to do with range.

 

[grady2hig]

If true, best answer here

Thank you!!

other people already said the same thing before this... you just didnt read it and then told them they "don't get it".

 

[crazychile]

@crazychile gets it!!!!

I wonder why??

Dunno. I have a red Jeep. You have a red Jeep. Maybe its some hoodoo telepathy between red Jeep owners.

 

[blessidsoul12]

Although...it would be awesome if the "fuel range until empty" estimate when you fill up was actually able to predict exactly how you will be driving on that tank ;-)

 

[Biscuit]

Wow way over everyone's head here. I'm not talking about gas mileage...????!!

No, it's way over your head. The range is an estimate, and it's based on your fuel consumption.

 

[Rubi Blue]

Not complaining...but what's up with such a variance in fuel tank range after I fill up?

When I first bought my Rubicon I remember the range would be in the 315-330 miles(to empty).

Now when i fill up my range varies greatly from lower 260-290??

I make sure to top it off the same every time i fill up and always costs the same.

I can see maybe a few miles off here and there, but why high range when new but now low varying ranges?

Any thoughts or the same for others?

I understand the question! and my answer is the on-board computer is learning and using a different MPG number internally and displaying the resulting range. When I first got Rubi, it showed 310 mile range. now, i don't see that anymore. Initially, they must have set the computer to use a HIGHER MPG (like what told EPA). Now, the computer is using what I actually get. Nothing to complain about here. Rubi is what my dreams were made of (already completed PowerLine at Brown's Camp... what a RUSH!).

 

[AK0311]

My guess, dealing with a Ram 2500 for 11 years and a Journey for 6 that do this, is that the computer is basing that range on your recent driving. So if you have been doing a bunch of in city driving, it'll show a low number, but if you've been cruising the highways, it'll show a higher number for the estimated range.

Just a guess though.

 

[photowiz]

This.....The range to empty(RTE) is calculated based on the recent MPG. So if your MPG has dropped, so will your RTE, even on a fresh fillup.

Agreed. The computer recalculated the RTE based on recent mpg.

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