Quick SG Question

[Arragonis]

Current tank I have trips averaging 60 MPG, some at 55 and some at 65.

Currently if I check how many gallons to fill up it says 1.3 for 101 miles. If I round this up it comes to :

101 miles / 1.4 galls = 72.14 MPG.

That can't be right ?

[Arragonis]

Nobody else, must be me then

[99metro]

Anything is possible, but realize that when you fill up you can be off a lot. My truck can be off as much as 3 gallons from the first click to when I actually SEE the fuel at the filler neck. You really should run the tank down to about a 1/4 or less for best results and then work on trying to get consistent fill ups.

The SG has a few things that can be tuned so be sure to check to make sure your speed is correct, type of fuel, tank size, engine size, etc. All those could give erroneous results.

My little 3 banger car can get incredible fuel mileage over short distances per the SG, but I use it as a guide for the overall tank. It all averages out in the end. Sure i could report 250 mpg over .01 miles, but that would not be honest.

[Arragonis]

Metro - thanks, I'll check the speed. George (also a little 3 banger BTW ) has a collar in the filler neck to stop people putting in diesel by mistake - diesel nozzles are larger than petrol ones here and George was also available in Diesel for a while. I fill up to the top of that collar each time so I know the fillups are consistent. Not always the same pump though, but I usually go to the same place and it is all flat.

Its just if I take the miles from the ODO and divide it by the gallons the SG2 says I have used on Fillup (I don't confirm at that point, I just take the reading) it comes to 70+ MPG. But no trip average on the SG2 has been over 65.

So the same instrument is giving me two different readings.

When I do fillup I found it was 3-5% out and I adjusted it halfway each time. I reset it last time though because it was suggesting I was getting 100+ MPG trips which was impossible as the first bar on the fuel gauge went out at ~ 100 miles - other owner experience ranges from 100 to 150 miles for the first bar.

[euromodder]

A SG is only as good as its calibration, so calibrate the car and the SG against a GPS and correct for the distance difference.

Dunno how it is on a gas car, but on my diesel, the SG is calibrated to the driving style as well.
Changing the driving style, the SG will be way off.

[puddleglum]

First, (unrelated to your SG) if you have an evaporative emissions system on your car, be careful about filling right to the top of the filler neck. You could flood the system and do some expensive damage.
As for SG, what is it saying for your tank avg. mpg? Does your SG odo match up with your dash odo? It sounds like a calibration issue to me. It took me quite a while to get mine set and I still have to adjust it from time to time cause it seems change.

[Cd]

I have a question for all of you ScanGuage guys : Do you leave the thing plugged in at all times ?
I have a SuperMID which is much like a MPGuinio and your ScanGuage, but the backlit display stays on even when the car is off.
I barely ever drive my car. How long would you go without unplugging your ScanGuage ?

[Arragonis]

Apologies, been busy this weekend so no posting.

Originally Posted by euromodder

A SG is only as good as its calibration...

Recalibrated the speed based on the Go! GPS built in. We'll see. More info below.

Originally Posted by puddleglum

...You could flood the system and do some expensive damage.

...It sounds like a calibration issue to me....

More info and clarification for the above - When I do the miles on the ODO vs the gallons to fill up on the SG2, the figure falls. At the start of the tank it can result in an MPG figure of over 70, and maybe later it drops to 65 or less.

I always round up, so if the SG says 2.2 gallons to fill up, I take it to 2.3. Its important to stress here I'm NOT actually filling up at this point, I just use it to monitor a tank seperate from the tank MPG.

I think this variation at the start of a tank has bvggered up my calibration - it was 3-5% out on a tank which is OK for me. However because we have had some time limited offers of discounts on fuel (supermarket offers 10 pence a litre off if we buy our weekly shop there but you have to use it in a week) I have had some tanks of only 1/3 or 1/2 normal length. So when I recalibrate at fill up it went out - for example it would record trip AVG figures of 80+ MPG, when I knew there was no way it could have been better than what I normally get, maybe 60-65.

Originally Posted by Cd

I have a question for all of you ScanGuage guys : Do you leave the thing plugged in at all times ?...

Yes, it goes off by itself after a few seconds. Sometimes if I switch off at lights I've found it doesn't come back on by itself, I have to hit the red button. Maybe a timeout issue.

[FXSTi]

Arragonis,

Hate to thread jack here, but I saw your mention of your dash camera in another thread. I don't have enough posts to be able to PM you so I though I would mention this here.

You mentioned not being able to set the date on the camera. You may already be aware of this information, but there is a website (Blog really) where the guy explains the clock setting procedure for many different kinds of inexpensive Chinese dash cameras. If you"re interested Google techmoan. He does a lot of great reviews on this type of camera.

Sorry about the thread jack

Kirk

[mcrews]

My understanding is that the "miles left" or Gallons to fill" are workng on the avg mpg and the instant mpg.
If you start 'city driving' to find a gas station at 50 miles left (after a 5 hour trip at 57mpg for example) then the new mpg(city driving) of say 25mpg, will erase the 50 miles left almost instantly.

imo, there is a matrix that wieght the instant mileage heavier as you run low on gas.