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

It wasn't a very long distance to travel, but it was all in town mileage.. A friend of mine kicked in on gas and said he'd fill it, so I took him up on it and went with it..

I had 104 mi. (this is the corrected mileage for the compensated tire size)
it took 3.111 US gal to fill

brings me to 33.43 MPG

reguardless of distance, mileage is mileage.. right? :confused:

I added it to my log, but I didnt want it to seem as tho I was cheating myself out of my log accuracy (or as close as possible) and i can edit as needed on it..

I'm trying to keep this by the book..
lemme know..

thanks :thumbup:

The smaller the fill, the more your MPG figure will be affected by factors like slightly over/underfilling compared to where you usually stop filling.

In the end it'll all even out. You'll know next time you fill up if it was an odd ball.

yea, When I fill up, my first 3 gallons are usually the best, cause I usually go for about 60 miles all highway, so the mileage bumps up. From there on it's rural-highway-rural-highway :(

mine was all 100% city stop and go, light timing, coasting, cool down, start up, cycle, ect..

I think I had 4 or 5 cool down cycle periods on this tank..

If it's going to, It'll even out on your next fill ;)

mileage is mileage when accounted for over time.

I fill my tank until I hear fuel climbing up into the filler neck. Then I click the pump until squeezing the handle gives only clicks: that suggests the filler nozzle is actually in the fuel. They're all about the same length, so that means I'm filling to about the same spot, every time.

A slight aside on instrumentation, Why The Heck do I see more automatics with tachos than manuals? I can't swear this is typical, but it seemed to me that when we were shopping for cars, if you wanted to stir the gears yourself you didn't deserve to know your engine speed. What's up with that?

My guess is that in the United States, low-end cars are usually manuals. Low-end cars are the ones that have corners cut in their manufacture (no radios, tachometers, side mirrors, etc.). I can't imagine a tachometer costing that much, but I guess a penny saved is a penny earned...

- LostCause

I'm thinking about reducing the size of my tank. I figure that not carrying around all that extra weight can't hurt. Granted, I'll be filling up much more often, but that will just help
my mileage log grow, right? ;)

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

Just put in less. I've experimented with this and saw no appreciable increase in MPG's with a 16 gallon tank filling to 5 gallons for several tanks with the SG(Scan Gauge) YMMV(Your Mileage may Very):)

^
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..

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..

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 :thumbup:

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

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

Chris -

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

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.

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.

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.