Scangauge accuracy

[Tango Charlie]

The SGII is high on my list of 'things to buy', so don't take this question as criticism.
Has anyone continued to calculate their mpg after a fill up to double check the SG's accuracy?
I imagine apathy sets in (as far as doing calculations go...) once you have it plugged in, but I'm hoping some have been curious enough to double check. What did you find out?

P.S. Yes, I know it won't work on an '88 Accord. It'd be for the wife's Vibe.

[dcb]

I've heard a few folks report 3% per tank. I'm sure instant mpg varies a lot more than that though.

[rjacob]

I have an SGII, and it is relatively accurate. Not dead on, but close. I still figure out my gas mileage everytime I fill up. The SGII also allows you to enter how much gas you really used versus how much it thought you used (when you fillup). So it will modify the future results.

[azraelswrd]

I intend to use both to measure my MPG. I've got 2+ yrs worth of data on Excel using the old way, so why stop now? I'm relying on my SGII for "on the fly" data though it will be interesting to see how much % adjustment I'll need to make after I refill the tank. (just did the "first tank" thing before adjustments today)

[Tango Charlie]

Bump.
Now it's MY Vibe, so the SGII has jumped to the top of my 'To Buy' list. Any one else have any feedback?

Originally Posted by rjacob

I have an SGII, and it is relatively accurate. Not dead on, but close. I still figure out my gas mileage everytime I fill up. The SGII also allows you to enter how much gas you really used versus how much it thought you used (when you fillup). So it will modify the future results.

I couldn't find this on their website. Is this info from the owner's manual?

[rjacob]

Here is the manual:
http://www.scangauge.com/support/pdfs/SGIIManual.pdf

Check out page 18 of the manual (20th page of the PDF).

BTW, The ScanGauge is probably the most cost effective way to improve your gas mileage. It will probably pay for itself easily.

[PaleMelanesian]

Mine paid for itself in about 5 months. A thirstier car, more miles driven, or higher gas prices (already a reality) will reduce that payback time.

I do all my calculations based on actual pumped gallons. The SG is a tool to help me improve, but it's not the final word. You click "more", then "fillup", and it shows how many gallons it calculated. You click left or right to enter how much you actually pumped, and it uses the % difference for the next tank's calculations. After a couple tanks, it'll be within a % or two each time.

[Schwabe]

Any tool such as the Scangauge can only help you adjusting your driving style to become more fuel efficient if that is your goal. In terms of actual MPG or distance left it is always based on average used so far and always only an estimation. it can get close but will never be exact. The more you "teach" the unit (aka adjust the actual gallons used at each fillup) the more acurate it will be. But what if you suddenly have a chance to coast for a long period of time just before your empty would come on. The range calculated was based on what your doing since the last fill up and now your driving might be completely different.

My actual calculated MPG based on fill up is alwyas less then what my SCII shows. Just my observation and I could further adjust the settings on the SCII with the help of a GPS etc I know but for me it does what I need. One indicator for me is when the MPG hits 80 I will shift to neutral and coast. I can see if I improved on my daily commute versus the day before etc. love the SCII but would really on it for actual MPG calculation for a whole tank or lifetime etc.

[PaleMelanesian]

Someone told me early on, "It may not be accurate, but the relative gains are true. Even if it's reading Ducks instead of MPG, just drive to maximize the ducks. The tank fillup will follow."

[dremd]

Works very well in vibe.
Works like crap in TDI.