Ultra gauge way off

Hoping someone can help. I've calibrated my ug, but my avg mpg and distance tol empty are super far off, like 750 miles and 16000 respectively. Any thoughts?

 

What year truck?

 

How did you calibrate?
The unit will self-calibrate fuel correction factor as you progress.
Don't reset the calibration or zero the total MPG... Let it go for 5 or 6 tanks, add the TOTAL fuel for all tanks, then plug that number in. It'll give you a more accurate correction factor. My '08 is at 1.093 after calibrating on 57.4 gallons today.

 

2011. Been doing the full tank instructions. Currently at 1.035. Don't think dte should be 15000 miles.

 

I do full fill up, but also enter in the exact amount of gas it took to fill up. This is what calculates the 1.035 I currently have. My instant mpg is off also. Reading 26 mpg at 65 mph.

 

From the instructions.

• Multi-fill-up Calibration:
  1. 2. 3. 4. 5. 6.
  

Fill up the fuel tank.


Set the ignition to the RUN position (Engine Off)


Press and hold the UP key to cause UltraGauge to recognize the fill-up


Zero the Average MPG. MENU --> Gauge/Page Menu .. --> Zero Ave MPG, G/H.


Exit the Menu system


Drive until its time for the next fuel fill-up.



At the next fuel fill-up, fill the fuel tank and note the number of gallons/liters used (pumped). (Always use


the same fuel station and the same fuel pump)


a. Repeat step 6. Proceed to Step 8 after 2-4 fill ups. 8.


Set the ignition to the RUN position (engine off)


Press and hold the UP key to cause UltraGauge to recognize the fill-up


Select MENU --> Vehicle Setup.. --> Calibration.. --> Calibrate MPG/Fuel, and change the value displayed


to the amount of total sum of fuel recorded in step #7. Press MENU when complete to set and save the


calibration.


Exit the Menu system the cal is complete




I am asking for help and don appreciate being talked to like a child. I read and follow these instructions. Why is my instant mpg way off as well?

 

I think you're recalculating it every time. I made that mistake too. Either that or you didn't go to the exact same fuel pump to calibrate.

 

do you have a 4 or 6 cyl? that could actually be your instant, it changes a bunch with a tiny change in elevation?

 

Whippersnapper is somewhat incorrect on the fuel calibration.

No, it does not need to be done every time, but it MAY need to be done occasionally as fuel blends change. Mine was running dead-on with manual calculations at 1.082, but about a month ago it became optimistic.
Changes in octane and ethanol content will impact the calibration, which is one reason UG says to use the same station and same pump. My change in accuracy coincided with my switching to premium for the hotter months to help keep the knock sensor happy.
I re-ran the calibration through 4 tanks and am now at around 1.093. I'll know how correct it is on the next fuel up.

BTW: Running premium on my 2.7 I'm not seeing any difference in actual MPG or power

I'm surprised you're getting 1.03. My UG was about 4mpg optimistic at 1.00 from the factory.
Like I said... leave it alone, and after 4 or 5 tanks, set the calibration with the TOTAL amount. Like I said, I used a total of 57.4 gallons to calibrate.

One tank of 14 gallons is not enough to get very close, which is why the instructions recommend 4 tanks, but the more the better.
You can run 10 tanks if you'd like, but when I got mine, I'd calibrate on every tank (I did not reset totals) and after 4 or 5 tanks I was finding the pre-input gallons within a hundredth or three and I wasn't seeing any change in the calibration factor.

Your instant MPG is off because it is not properly calculating your fuel usage, and possibly not properly calculating your distance.
That said... 65mph, depending on whether it's uphill or downhill, my instant MPG could be anywhere between 8 and 200... flat and level roadway at 65, I would not be at all surprised to see 26.


On your DTE, that's a function of current MPG (not instant, most likely "SRT" which is average since last reboot) and tank size.
When you tell it that you filled the tank, does it confirm 21 (or actually, 21.1) gallons, or is it higher?
I don't recall what the factory default was for the tank size, but I had to adjust it.

You may have to calibrate distance as well. Mine was off slightly. UG uses the same data source as the speedometer/odometer, so there may be some variation against reality. Personally, since I drive by the odometer, I don't mind if the UG is a little off from the GPS as long as it matches the odometer... but even at that, I think I have a small correction factor of a fraction of a %.

 

I know it's a difficult quote to read because of the dead images....

Says right there to repeat the fill/drive cycle 2-4 times before proceeding to calibration.
They expect a 25-50 gallon calibration number, not a single 10 gallon fill.


You mentioned that your UG was not that accurate on fuel used, and we speculated that part of this may be due to the injector shutoff on high speed decel at 0% throttle, but another part of it may be your calibration being off.

 

Right... you only need to calibrate once (unless you change octane or ethanol content), but you need to give it enough data to work with for an accurate calibration.
A single fill up is not enough.


And ya... in retrospect, there's a lot of reasons that I'm kicking myself for not getting the SG. I like the UG, but I think I'd like the SG a lot more.

 

But you do tell the UG how much you burn each time. That is the gallons used, which in turn affects your calibration factor.

I did it for 5+ fillups, each time. The UG got more and more accurate, until it's gallons used was only off by a few tenths of a gallon. When I quit calibrating, it was nearly dead on.

Now I just use it to get a relative reading of how I'm doing.

 

Correct.

You CAN keep a running total and update the calibration as long as you want and it will constantly "fine tune" (unless you change octane or ethanol), but as you and I have found, after 4 or 5 fill ups, it is so close that it's not work messing with unless something seems wrong, which is what happened to me when I switched to premium last month.

 

This is my fifth fill up. At each I hold down the up key until full tank is reported, then go in and manually enter the amount of gas I just put in the tank. The ug has been off by no more than a gallon, which tells me that it is fairly accurate on my fuel consumption. How can it be accurate on my consumption but tell me that I have 15678 miles until empty?

 

Did you remember to zero avgMPG and everything else the manual said to? First time I held up for a refill, inputted gallons used, but did t zero anything and I think I saw the same crazy numbers as you.

DTE is based on avgMPG, which jumps dramatically until you get close to empty. On this tank my avg was up to 27, down to 22, now at 23.5 with only 2-3 gallons used.

 

The UG keeps a running count of distance travelled. By inputting gallons used, it divides its distance by your gallons, giving MPGavg.

If you forget to zero distance travelled at each fillup, distance constantly increases, increasing, falsely, MPGavg.

When i forgot to zero distance on my first fillup, all my numbers jumped up dratically at the second fillup/calibration. I had to start the whole calibration hing all over again.

 

Only because you didn't add your previous fillup.

If you zero every time you get gas, then you are constantly resetting it.
You'll eventually sneak up on a good calibration, but it may take longer.

If you don't zero, then you simply have to add your previous tanks to the current tank to get the proper correction factor.

Like I said... Yesterday I filled up and recalibrated with 57.4 gallons.
That was 4 tanks. That's exactly what the instructions that the OP posted say to do.

Hint... When you go to the calibration screen and you see "32.503" already there, you should not change it to "16.538" that you got on that fill up... you need to add the previous fillup to the current.

I save my outgoing Fuelly text messages for a month or so, so I can go back 5 or 6 tanks and add totals if I want to recalibrate.

 

I agree that is a better, easier way, but I think the OP's outrageous numbers may be due to not zeroing distance and not adding all the fuelups. My guess is he's calculating per fuelup like I did, but without zeroing distance, which would lead to Falsely elevated numbers.

OP, if you saved your receipts or fuelly'd, maybe you can track down where the problem is.

Hmm, I could have sworn my instructions said to zero and calibrate every fillup...

Edit: my derp, resetting MPGavg resets general distance travelled. I thought these were seperate.

 

I am going to factory reset and start over. What steps should I take at the next fill up and what steps should I take for the next several fill ups after that first one??

 

The instructions you posted are perfect.

First, before doing anything, go through the Vehicle and Gauge setup and get what calibrations you can set.
This includes speed, odometer (set them to GPS or to your speedo/odo, your choice), tank size, and whatever other options there are under the setup menu.

Go to the gas station, zero everything, and fill the tank to the first click-off.

Now, you can go one of two ways... you can adjust the fuel calibration on each tank, or you can simply ignore the UG for 4-5 tanks and do it all at once.
Regardless, keep your receipts or write down the # of gallons (all digits to the .000).

Each time you refuel, press the "UP" button to tell the UG the tank is full, then go into the menu.
Select Vehicle Setup.. --> Calibration.. --> Calibrate MPG/Fuel.
For your first tank, the number will be pretty close to what you purchased.
Adjust the number to match your purchase and keep the receipt or write down the fuel amount.
I recommend writing down... as hot as it is right now, the thermal receipts may not last long in the cab of the truck.

Next time you refuel, do the same thing, but instead of making the calibration number match the quantity you purchased, ADD both purchases together and input that number. Again, the number displayed should be reasonably close to your total purchases.

Next time you refuel, do the same thing, but instead of making the calibration number match the quantity you purchased, add all three purchases together and input that number. Again, the number displayed should be reasonably close to your total purchases.

Next time you refuel, do the same thing, but instead of making the calibration number match the quantity you purchased, add all four purchases together and input that number. Again, the number displayed should be reasonably close to your total purchases.

Next time you refuel, do the same thing, but instead of making the calibration number match the quantity you purchased, add all five purchases together and input that number. At this point, the number on the UG should be within a couple of hundredths of your total of the 5 purchases.


Once you're happy with accuracy (and there will always be some small variance), from that point on, ignore the calibration procedure.
You can reset the total MPG and G/H without impacting the calibration, or what I do, it leave the totals alone and simply zero my trip data from tank to tank unless I'm going on a road trip.