Help with scangauge II calibration - Fuel Economy, Hypermiling, EcoModding News and Forum

wildfire8 · 01-18-2010, 01:46 PM

I have had a scangauge for about a year and a half and have never had it properly calibrated. On my 2006 hyundau elantra gt I have an average mpg gauge and a miles to empty gauge. But the numbers on my dash and the numbers on my SG have never been the same. my car is a 2.0L/14.5gal/gas. I have the SG set to 2.0l/14gal/gas. My calibration percentage has gone from -12% - +12%. All I have been using my SG for is a guide to get better mpg. I calculate every tank when I feel up and it never matches the SG and a lot of the time my dash either. So is there anything I should be doing different?

SentraSE-R · 01-18-2010, 03:08 PM

Nope. Mine jumps all over the place, too. I just set mine with the highest calibration number for each car, and surprise myself if/when I beat the figure with the tank fill.

wildfire8 · 01-18-2010, 03:17 PM

My girlfriend has a scangauge in her Kia Soul and with in the firs or second tank it was perfectly calibrated. When she filled up the SG said she used the same amount of gas as she put in. I don't get it.

Lazarus · 01-18-2010, 03:39 PM

Filling technique is critical. Make sure during the calibration period that you run the tank to empty and not just 3-5 gallons. Fill at the same pump and use the same technique every time. If you just go to the automatic shutoff on the pump then do that or if you go to the next shutoff then do it the same every fill. Consistency is key.

I had mind down to .1 on every fill. If you are already doing these things maybe there is something else going on. Unless your unit resets itself every once and awhile and goes to the default setting.

wildfire8 · 01-18-2010, 03:52 PM

I am trying this time to go to the auto shut off. My SG started tweaking last tank so I am still in process of celebrating again.

tim3058 · 02-27-2010, 10:39 AM

Glad to see I'm not the only one having calibration issues. My MPGuino varies considerably every tank from the actual pump receipt, last fill-up it was 4.12% low, tank before that was 13.65% low (and I haven't touched the Usec/gal inputs). Now I always end up filling up at different gas stations so that could be a big part of it, but has anyone encountered a randomly varying error like this?

wildfire8 · 02-27-2010, 11:23 PM

Just filled up a new tank and I did use the same gas station last time but a different pump #4. I used the same pump #4 this time. My SGII said 12.7gal and I filled up 12.721gal. I was so surprised to see that. I might have it calibrated. We will see on the next tank.

gone-ot · 02-28-2010, 01:22 PM

...using the "same pump / one-click" method, I've gotten similar results with the last three tank fillups; this afternoon will be fillup #4.

Addendum: fillup #4: SGII said 8.4 gallons; pump said 8.397 gallons

PaleMelanesian · 03-01-2010, 01:10 PM

I calibrate to the running average offset. I track SG predicted gallons and actual fill gallons in a spreadsheet.

Another way to approximate this is to adjust the offset to halfway between the two each time. If the gauge tells you 10 gallons and you actually pumped 10.4, adjust the calibration to 10.2. After a couple fills, it'll even out nicely.

gone-ot · 03-01-2010, 01:46 PM

Quote:

Originally Posted by PaleMelanesian

I calibrate to the running average offset. I track SG predicted gallons and actual fill gallons in a spreadsheet.

Another way to approximate this is to adjust the offset to halfway between the two each time. If the gauge tells you 10 gallons and you actually pumped 10.4, adjust the calibration to 10.2. After a couple fills, it'll even out nicely.

+1 on the spreadsheet

+1 on the "split-the-difference" offset steps rather than all-at-once step.