Anyone else's overhead computer way off?

[Po' Riggity]

Re: computer

Originally posted by W. A. Derby

John - K5AWO



That is might damn interesting. It explains a lot.

Thats a major reason that I have started hand calculating everything, because I don't trust the accuracy of computers. . I calculate after every tank.

Scott

 

[SLinse]

Mine is showing 4-5 mpg better than what I'm actually getting. Overhead read 21. 8 and hand calc was 17. 7!! kinda bumbed that's waaaay off!

 

[Po' Riggity]

Wow. . I guess I am kinda glad I dont have that problem. . but even so, if you are getting 17. 7 thats still good in my opinion.

Scott

 

[Carlsummers]

I have 11,000 miles on my '03. Hand calc over the past 6000 miles, I am averaging 19. 3... overhead says 18. 9... . that's close. I run until the mte is close to 0, and it only takes roughly 30 gal. to fill up... I do use the same pump and same nozzle every time, unless we are out of town (which is very, very seldom).....

 

[swaite]

If I use the wait and add method of filling the tank, I notice the DTE reading will start at around 500 miles and then stay there until the fuel guage drops off the full peg. My guess is that by carefully adding fuel after the nozzle first clicks off I am "overfilling" the tank from what Dodge intended. The fuel sensor has no way of knowing how much extra fuel is in the truck so it calculates based on what it considers full. After using up the excess the DTE begins to drop along with the fuel guage. BTW, I've recently slowed down a little and noticed a significant improvement in milage when travelling 65 versus 75.

 

[Takomax]

My overhead computer is off too.



I have an 04. 5, 3500, 3. 73, 6 speed. I get about 19 mpg with a mix of hwy and city.



If all hwy and IF I drive around 65 instead of 70mph I get 20 or 20. 5.



My overhead says I get 16. 5 or 17 something.



When I fill up I cannot get much fuel after it clicks off automatically. I mean less than . 5 galons.



I have calcualted this about a dozen times at filling stations; My calculator says 19. 5 to 20. 5mph and my overhead says 16. 5 to 17. 5. I gotta go with my calculator.

 

[JHardwick]

I've just recently become involved in this mileage vs. overhead debate which has been going on as long as I've been around.



I just today wrote down mileage after a fill-up.



I've got 47,000 miles on my truck and have not reset the overhead for probably a year ... ... ... ... . it reads 17. 9-18. 0 all the time.



My fueling routine varies, but typical is a fill or a quick 15 gallons. I have only been below 1/4 tank a couple times and have never seen the "low fuel" light.



When I fill, I let it go til it clicks off and wait a second, then hit it again with another . 5-1. 0 gallons and thats it.



I'll keep track of the number of gallons I pump over the next couple of weeks and then total up the miles and see what happens.

 

[Dean Upson]

Mine is normally within 1 mpg and often within . 5 mpg. Close enough as the actual hand-calculated mileage is more. I am careful to actually fill up the tank and not just stop when the pump turns off, you cannot figure accurate mileage on foam.



Dean

 

[stevenknapp]

I run until the mte is close to 0, and it only takes roughly 30 gal. to fill up...



If you read the owners manual you'll note that it's designed that way. I forget the exact numbers, but both indicated that empty wasn't really empty. The said this was to prevent folks from running out of fuel when towing heavy loads.

 

[FDrake]

My overhead gauge is very accurate. I wish it weren't. I also miss the actual mileage readout while driving like I had in my '02. I get 13. 5 around town (very short trips). I get 12. 5 towing at 19,640#. I was hoping the MPG would be close to what I got with my 2002 HO diesel but it aint even close. I got 17MPG around town with it. The total empty weight difference between the 02 and the 04 is 300#. I hope it gets better, WAAAAY better.

Frank