ScanGuage II vs. Calculated MPG

[lpittman]

Hey everyone!

Got my ScanGuage II and was surprised, then alarmed by the MPG it was reporting. From my tracking and calculations my runner has been averaging right around 15 MPG. Low, I know, but I do 90% city driving (to Uni and back every day). But then I plugged in my ScanGuage and watched the AVG (MPG average) for a few hours while driving around and it was right around 20/21 MPG. Awesome!

But - why the big discrepancy? I know the ScanGuage may need to be calibrated (hasn't gone through a full tank yet) but would that really account for that much of a difference?

I'm slightly worried I may have a slow gas leak somewhere ...

Any ideas? Or do I just need to calibrate it and chill for awhile.

Cheers!

Luke

 

[4-Ripcord]

1- make sure you went through the settings properly (engine size, gas tank size, offset speedo for big tires..)

2- Give it atleast 3 tanks before you start believing the AVG MPG part and the tank MPG, and make sure you go through the fillup procedure.. but still use the instantaneous MPG part to help you get better mileage.

3-There are some trips to the store where I get an average of 25 mpg over about 6 miles, but on the whole tank I still get 19. So don't let the report from one small cruise let you think the whole tank is gonna be that good.. unless you really focus on it being that good.

 

[white_n_slow]

If your tires aren't stock, you will need to do some math to figure out how far you actually drove. Or measure distance using a GPS, but this method works better on a road trip where you will burn through a whole tank in one trip.

 

[lpittman]

Alright, good points guys, thanks... I knew it would be out somewhat, but didn't think it would be that much. I'll get it dialed in.

 

[Greg_Canada]

Mine is typically 15-20% off depending on driving type, weather, etc. You will definitely have to adjust it. It's doesn't do anything magical to make your MPG better, LOL...

 

[Whitson Metalworks]

it took mine a few tanks but once dialed in it works great. if you keep the instant mpg and tps readings on the display and stare at it as much as i did, your mpg will go up. its a great driving coach.

 

[4-Ripcord]

it took mine a few tanks but once dialed in it works great. if you keep the instant mpg and tps readings on the display and stare at it as much as i did, your mpg will go up. its a great driving coach.

X2 on that. My mpg went up a bunch when I first got mine.

i watch it more than I watch the road.. ok not that much but you get the idea.

 

[Nelsonmd]

Mine is typically 15-20% off depending on driving type, weather, etc. You will definitely have to adjust it. It's doesn't do anything magical to make your MPG better, LOL...

I think I usually run around 7.5%. It shifts up a bit (to about 9%) depending on the season, and whether my tires are pumped up all the way, but I have stopped adjusting it now and leave it at 7.5%.

It definitely helps control my driving habits. The AVG usually ends up being 1MPG higher than my tank average, which I think is pretty good.