Official Scangauge II Thread - Share your Data, Discuss Settings ,Problems, Findings!

[CTScott]

Originally Posted by jambo101

As an instrument to measure MPG my Scangauge is useless and cant be trusted to give an accurate reading..

With a full tank of gas and sitting at the gas station I put in all the required parameters for setup in miles and gallons as the trip was entirely in the USA,also included an Xgauge setting to show me average MPG per day,went to the fillup and pressed DONE then off for a 2000 mile trip,MPG read steady at around 36MPG through the first tankful but when i refilled the tank with 8 gallons of fuel going to the fillup icon it said i just put 12 gallons in so i adjusted/recalibrated the 12 gallons back to 8 gallons and started off again but now the MPG reading was reading a steady 25MPG.Throughout the trip the amount of gas i actually put in got further and further away from reality and i saw fluctuations as low as a steady 10MPG to as high as 90MPG The problem was probably my my fault but i cant figure out what i was doing wrong as the set up is quite straight forward and subsequent fillups should have read very close to the amount i was actually putting in the tank but in reality that fillup number just got further away from actual gas input..
Any one got an idea whats going wrong?
And can anyone suggest a less problematic MPG device?

Thanks

The problem with how devices like ScanGauge, Ecometer, etc. calculate MPG is what they do when the car is standing still. If the car was always in motion it is very accurate, but as the ratio of in to not in motion increases it becomes a crap shoot.

As for the 10MPG to 90MPG fluctuations; That is actually normal. When the Yaris is under heavy load the MPGs decrease significantly. For example, driving up the 1/2 mile hill of the road that I live off of, I see a pretty steady 8-12 MPG. Coming down it I start off in the 80-90 MPG range (when my foot is still on the pedal) and I quickly hit DFCO where the scangauge shows 9999.

How DFCO is handled is probably another issue with how these devices do their calculations as well. You have infinite MPG during this period, so depending on how you average that in can skew things quite a bit in the opposite direction of averaging the theoretical 0 MPG while stopped.

[YHWilliam09]

The only time my ScanGaugeII hasn't been very accurate was the first tank or two before setting it up. After that, it has been within 1mpg accurate on every tank. Maybe you got a faulty device, but I don't know.

A lot of people also love the UltraGauge, and it's less than half the price of a ScanGauge.

http://www.ultra-gauge.com/ultragauge/

I don't have any experience with an UltraGauge, so I can't tell you if it is any better or not. I do love my ScanGaugeII though.

[AGDS91]

Hi, ScanGauge it's compatible for JDM Vitz RS 2005 ncp91-AHMVK?
Es compatible con ese modelo?

[pribek]

Yes it is.