mileage is mileage, right? (question about accuracy of small fill)

[DifferentPointofView]

^
Cause if you don't have a scan gauge, you'll never have accurate fill ups... cause you'll never know how much fuel you used and how much to put back in to get accurate fill-ups..

[Chris D.]

how does a scanguage give you accurate fuel used data? does it know the size of your fuel tank, your injector pulse rates, voltage to the pump, regulator settings?

I dont see how it could be any more accurate than anything else..

[trebuchet03]

Originally Posted by Chris D.

does it know the size of your fuel tank, your injector pulse rates, voltage to the pump, regulator settings?

Tank: Yes - you tell it
Injector Duty Cycle: Yes
Pump Voltage: Implicitly (but this doesn't matter so much)
Regulator Settings: Implicitly

It knows no more than the on board engine management does

It's also calibrated by the meat person operator @ fuel up. The more you use - the more accurate it gets

Mine has been spot on for quite a few fill ups now LinearLogic did an awesome job programming the thing

[cfg83]

Chris -

Originally Posted by Chris D.

how does a scanguage give you accurate fuel used data? does it know the size of your fuel tank, your injector pulse rates, voltage to the pump, regulator settings?

I dont see how it could be any more accurate than anything else..

I agree, so I don't use the SG for reporting my MPG. I use the GPS adjusted odometer and multiple tank fill-ups for my fuel log. The SG has a "cheat bias" that you use to calibrate fill-ups. If you change the way you drive between fill-ups, or you're driving context changes, there is the possibility that the cheat bias would lose validity between fill-ups.

The SG requires that you input the size of the engine in liters, a speed adjustment based on non-OEM tire size changes, and the tank size.

From what I can tell, the SG does not know about injector pulses, 02 sensors, or fuel trim. If it did, I would expect it to report that data in the instant gauges, but it doesn't.

I only trust long term MPG, so I look at my MPG over 90 day fill-ups. The problem with my methodology is that is is harder for me to claim improvement of mods that have small effects on MPG.

I think the SG is a fantastic *relative* MPG barometer. With all else being equal, it can tell you that you are increasing or decreasing MPG consumption.

CarloSW2

[MetroMPG]

Originally Posted by Chris D.

Why was my post edited/altered without my knowledge? (title)

To make the subject matter of the thread a bit more self-explanatory. I do this sometimes - adding a few words on to a title in brackets.

[getnpsi]

When i dont fill to the click, I'll do exactly what svoboy does on his log. On my next fill i add both of them, even if the fuel quantity bought is higher than the capacity of the tank. The distance traveled is still constant.

[NeilBlanchard]

Hi,

If you under fill a tank, your FE goes up, but the FE on the next tank will go go down by the same amount.