Scanguage users - accuracy question
 

Just a question for people running Scanguages. I have noticed that mine seems to be consistently wrong in measuring fuel consumed and mpg. It seems that I am consistently using about 5-10% more fuel than the Scanguage shows. As a result the gas mileage shown by the Scanguage is about 2 mpg higher than what I come up with calculating it the old fashioned way. Anyone have similar issues?

Also, does anyone know how the Scanguage measures how much fuel has been burned? I would think it must be using either the MAF sensor and/or the O2 sensor, but Scanguage cannot show any data from those sensors so I dunno.

Welcome to the site

You have to tweak the scan gauge to the car. When you fill up there is a screen that lets you change the amount that the scan gauge calcuated and what you actually used. If you fine tune it this way with large fillups it should be right on. I did two 10 gallon fills on a 12 gallon tank and mine is with in .1 every time. If you have done this and it's still reading differnt everytime then I think you have a problem with the SG.

i am just now setting up a fuel computer i bought in Europe that uses the vss and the pulse width to calculate real time fuel econmy. Will work on any gas engine with multiple fuel injectors. The user calibrates the device to the individual vehicle. It doesn't rely on On-Board Diagnostic (OBD) generated data. i will post my findings when i am confident in the data.

diesel_john -

Very cool. Looking forward to your results.

CarloSW2

Wow, I never thought of that. I always look at that screen and just hit "done", it never occured to me to try correcting it. Thanks for the tip.

Mabey you've got dirty injectors

Run some injector cleaner in the tank

If your injectors are dirty they're not shooting the amount of gas the computer thinks it is.

The scanguage uses engine load to calculate fuel economy. Unfortunately it does not look at injector pulse width and VSS to calculate which is much more accurate. Engine load comes from MAP, IAT, and RPM/TPS. There may be a few more variables involved but that's the gist.

Hopefully Diesel_john's tool turns out to be a winner. Do you have to tap the injector wires John?

Since this thread was resurrected I just thought I would mention that my Scangauge II is now properly calibrated and very accurate. :thumbup: Calibration is +5%