Scangauge

[Taylor95]

For those of you who have the Scangauge II, how accurate would you say the current version is at measuring fuel consumption and mpg? I want to get something accurate for my Jeep. I tried the Torque app but it really overestimated my mpg. I know that my Jeep is pretty good for what it is, but there is no way it is getting an average of 45 mpg unless I'm going downhill with the wind helping...

[mpg_numbers_guy]

Both the Torque app and the Scangauge have to be calibrated to display accurate fuel economy. That being said, Torque was always 2%-10% off for me at fill ups -- overly optimistic on back roads and quite underestimating my fuel economy on the highway. From what I've read on here the Scangauge can be calibrated much more accurately.

[ennored]

ScanGauge allows you to adjust the speed (and thus distance) and gallons used. Both can be set to a pretty wide range, but real speed and real gallons is what should be used, if you want realistic fill up and distance to empty data.

That said, the way the ScanGauge, and other devices, calculate fuel flow is strange. It uses the airflow data and multiplies that by the nominal stoichiometric ratio to get fuel flow. Why it doesn't use the fuel flow data right from the car is beyond me. It doesn't even use the open loop data that's there to adjust it for when you aren't running closed loop.

Big thing NOT to do is to try to adjust it every fill up. Track a few fill ups and tweak it as you like.

[Taylor95]

That's helpful. I had no idea you could even calibrate the torque app. Maybe it was because I had the free version. I may invest in a scangauge sometime in the future. It sounds like its a lot better than the app.

[mattrod]

Try fuelly.com. It helps you calculate and track your fuel consumption.

[2016 Versa]

I know this thread is a few months old, but you can also get a device called Ultra Gauge. I have an older version of both the SG and UG. They can both be calibrated. My Scan Gauge shows 1 page with 4 gauges, my Ultra Gauge can be set to display up to 3 separate pages with 6 gauges on each page. Ultra Gauge also costs less. I'm not sure about changes to the newer SG but I think the newer versions of the UG can display 4, 6, or 8 gauges per page and up to seven separate pages. That's up to 56 gauges which gives you lots of information about mileage and the way your car is operating.