Mileage discrepancy 03

[Iguide]

Well after reading different threads about mileage and seeing that some folks were checking their millage by hand against the overhead, I did also. What I found was a two to three miles difference per gallon. With the overhead usually being the higher.



My Question is, Why is there such a discrepancy and can the computers be programed to be accurate?

 

[Prairie Dog]

Dodge just wanted to give you that warm fuzzy feeling and figures were not going to second guess them by checking it by hand.

 

[SRadke]

After adding a fueling box mine is off as well. It was very close before that.



-Scott

 

[Pawpaw]

My overhead typically runs about 2 MPG low.

 

[DFrank]

mine usually runs 1 lower than actual hand calcs. No box yet, but thinking the VA is looking better and better.

 

[Eric_77]

Well I think it uses some sort of averaging. When I pull trailer it shows high then the next couple of tanks it reads low after pulling trailer then t comes back to within a . 5 mpg after a few tanks of normal driving.



I also reset all the trip computers each time I fill

 

[Dean Upson]

Mine is normally within . 5/gal. I also reset each time I fill and I always try to get all I can into the tank.



Dean

 

[Iguide]

Milage 03

I also reset mine at each fill up. The last few times the attendant has filled it & even though I tell him to put in as much as possible I don't think he puts in as much as I do.

 

[Tony T.]

My overhead computer usually shows a higher reading compared to hand calculations an I reset it each time of fill up. It has been as close to . 2 an as far off as 1. 5. A lot of my driving is two-lane highway to work with red lights an such. An if we take a usually once a week 50 mile round trip to go eat at this certain restaurant, I'll see 16 to 17 mpg when I fill. If not just back an fourth to work an running around town I see around 15 to 15. 5. I have now 16,800+ miles with very little towing.

 

[GerryDrake]

I mostly reset mine only at fillups, and do the hand calculations. Towing or not, or combination, it is rarely off by more than 0. 1... . I do squeeze in as much as I can every time. .



Very satisfied with the accuracy. .

 

[Jengle]

Mine is usually within . 2 of hand calculating. As of yet, I have nothing in the line of bombs that would throw it off.

 

[Shooter]

16k+mi and it runs +/- . 2 towing, MT or combo.

 

[Johnstra]

Mine used to be spot on. Now it's 2 MPG less than hand calculated. I can't figure that out. Now my truck does have a new ring & pinion. I know almost nothing about differentials. I wonder if a subtle difference in setup on the rear diff can affect the gear ratios and consequently the computer's calculation of fuel economy. Anyone know the answer?

 

[jimnance]

My '99's overhead always showed 2-3 MPG better MPG than actual. After installing the Edge it got worse.



My '03's overhead was pretty accurate when stock. Within about . 5 MPG. With the Edge I'm showing about 3. 5 MPG higher than actual.

 

[amsoilman]

Anytime you add a FUELING BOX, the overhead computer will go BONKERS!



Wayne

amsoilman

 

[Prairie Dog]

I've read about lots of guys having their overheads go crazy too but I checked my mileage for the first time since adding the TST - The over head was high by 1. 9 MPG as usual.