i have noticed that the mileage reading on the overhead has been dropping below 10mpg in the city and highway, even resetting it would not make a difference. Well last night while waiting on a train I noticed that the mileage reading was increasing as the truck sat and idled..went from 9 something to over 16 in a few minutes. This is Edit backwards.
Anyone else have this happen? Cause??

 

Maybe you have it set to the metric side?

 

I have zero to little faith in the overhead readout. I'd like to know more about how it works and where it is getting its information from and what info it uses to calculate things. My mileage is always 2 to 3 mpg off when hand calculated, the temperature is alway 4 to 5 degrees off compared to any other thermometer I have and the everage econ is worthless. When sitting idle, the instant econ reads 0. Does the average econ factor this in? If it did, anything averaged with 0 drops pretty dang fast. If not, when does the computer decide to start factoring back in the info, at 1, 3, 7, 10, ??? Like I said before the rant, I have little faith in it all. IMHO the overhead is eye candy to sell the trucks and has little to no use for calculating anything. If we designed things here that are no more accurate than those stupid things, there would be a navy ship on every beach in the world. DTL (distance to land) = 120 miles, opps, I meant 0.

 

my overhead mpg is just about right on .2 or .3 off at the most

 

The whole display probably needs to be reset. There are instructions in the owner's manual. I think you have to hold down a combination of buttons at startup.

 

thanks..I'll check the manual

 

4x4dually,

I didn't know there was an instant econ mode. How do you get to that, I only know of average econ.

Mike

 

I'd like to know also. My 2000 did real time and average, but my '05 only does average.

 

my 02 had both Ican only find the one on my 05

 

The 99 only has average, a friends 02 has instant and average, average is always within .5-1mpg so i figured itd be nice, then the darn 04 didnt have it. Darn those dodge robbies

 

my 04.5 only has average, but when you reset it, its kinda like having instant, it moves so much :laughing:
Scott

 

surfram, the manual says to hit the reset button twice within 4 seconds, tried that and the readings stabilized, but they still read low. I'll have it looked at if it goes in for any service.
I kinda like the overhead, but still keep a logbook of the fuel going in, it's easier for me to look up than use a calculator.

 

The computer gets it's reading from the ECM I believe. It monitors things like throttle load, incoming air, fuel, timing, blah blah blah. It then takes those readings and says "ok, I have X amount of fuel and Y amount of air coming in so I should be getting Z amount of mileage". That's what it displays. The problem with that is that it is making those numbers off of averages that the computer has stored. If your throwing in so much fuel, the computer says you should be getting this kind of mileage whether you actually are or not. It's not real time numbers, but averages. The technology is slowly coming along where you will actually be able to get real time numbers from real time data, not just averages. If your confused I apologize but I'm having trouble explaining it.

 

My OHC has consistently been within .1-.2 of my hand calc. . . thats over the last 4 fill-ups. .... seems pretty accurate to me.
-daniel

 

i figured it just measured x amount went into the engine x amount came back in return im driving this fast so im getting yada yada mileage