Accurate measurement of gas tank level

[Morritse]

The gas gague does NOT read accurately. Watched it while filling up. Was not linear at all. Since I run a bunch of different ethanol blends, I need to know the tank level. Is there another way to check tank level?

[cspcrx]

I have been gathering data on this over the last month or so for that very reason as well, blending fuel. I have been recording fuel levels, gallons of each fuel type to get a picture of how many gallons it takes at E, 1/8, 1/4, 1/2 and 3/4 tank. My numbers are pointing to my car having a 16.9 gallon tank which matches the manual. Here is what I have been able to put together based on my fueling stops for the different levels. Still working on E as I usually don't let it get down that far.

Gallons to fill at
3/4 4.225
1/2 8.45
1/4 12.675
1/8 14.7875

I have access to flex fuel which measures 51% ethanol at my local station. I have found that a 1.3 to 1 ration of 91 to flex fuel yields me a E28 blend that is 95 octane. You will need to know the actual ethanol rating of the fuel at your station. I use a fuel-it tester, simple tube that you add fuel and water to.

hope this helps you

[Morritse]

I have been gathering data on this over the last month or so for that very reason as well, blending fuel. I have been recording fuel levels, gallons of each fuel type to get a picture of how many gallons it takes at E, 1/8, 1/4, 1/2 and 3/4 tank. My numbers are pointing to my car having a 16.9 gallon tank which matches the manual. Here is what I have been able to put together based on my fueling stops for the different levels. Still working on E as I usually don't let it get down that far.

Gallons to fill at
3/4 4.225
1/2 8.45
1/4 12.675
1/8 14.7875

I have access to flex fuel which measures 51% ethanol at my local station. I have found that a 1.3 to 1 ration of 91 to flex fuel yields me a E28 blend that is 95 octane. You will need to know the actual ethanol rating of the fuel at your station. I use a fuel-it tester, simple tube that you add fuel and water to.

hope this helps you

Thanks. Exactly what I needed.

[cspcrx]

This is what I am finding with my car so you should really look to see how yours is. I thought I saw a YouTube video online of someone doing a VAG COM to change how their fuel gauge read.

Glad that helps.

[Morritse]

So half full on the gague took 6.5 gallons to fill up. Guess I need a different calibration curve

[cspcrx]

That seems way off. So you gauge showed 1/2 tank and it only took 6.5gals to full. WOW Something is off there. since your running full E85 curious if things are getting gummed up have you run some of that Ethanol cleaner through it? I presume our cars have a float type fuel sensor. Have you ever noticed your gauge moving oddly or not at all?

[Midnight_Rider]

Gallons to fill at
3/4 4.225
1/2 8.45
1/4 12.675
1/8 14.7875

So, on 1/4 is 4.22 (4.225) gallons. That means, when it empties, it's 16.9. I tent to fill at 14 gallons on empty (red)... thinking that there is 2-3 gallons emergency reserve. Is this not true?

3.725 gallons per 1/4 tank with 2 gallon emergency reserve, then it'll be 14.9 gallons. I remember on remote highway on this car with the empty fuel light on, fuel gauge pegged all the way down and drove at least 3 to 5 miles (can't remember exactly).

Also excuse my math if it's wrong, I'm drunk.

[Morritse]

We're supposed to have 2 gallons left when range hits 0.

[jygesq]

You should never let the remaining fuel to get so low, the fuel also provides cooling for the fuel pump,& you do not want to get any crud in the fuel to get into fuel injection system.

[cspcrx]

Yes the feeling is at E there is still about 2 gallons in the car. But as you can see from my data my gauge is not reading like that based on my fill ups. I think mine is closer to 1gallon.

[u2nelson]

I have been gathering data on this over the last month or so for that very reason as well, blending fuel. I have been recording fuel levels, gallons of each fuel type to get a picture of how many gallons it takes at E, 1/8, 1/4, 1/2 and 3/4 tank. My numbers are pointing to my car having a 16.9 gallon tank which matches the manual. Here is what I have been able to put together based on my fueling stops for the different levels. Still working on E as I usually don't let it get down that far.

Gallons to fill at
3/44.225
1/28.45
1/412.675
1/814.7875

I have access to flex fuel which measures 51% ethanol at my local station. I have found that a 1.3 to 1 ration of 91 to flex fuel yields me a E28 blend that is 95 octane. You will need to know the actual ethanol rating of the fuel at your station. I use a fuel-it tester, simple tube that you add fuel and water to.

hope this helps you

Those numbers to fill indicate the gage is very accurate.



Sent from my iPhone using Audizine

[cspcrx]

Those numbers are based on 16.9 gal tank and mine has been tracking very closely to these numbers. As a result that is what I am using as a guide for my blends.

[Morritse]

Do b8 have a smaller gas tank? I've run my tank completely empty before and it only took 16.

[ModItNow]

So a 6mt has a 16.9 gallon tank instead of 16.1? I always thought DSG and manuel were 16.1. I read the fuel level from OBD Fusion too but I don't think that's accurate either lol

Sent from my SM-G965U using Audizine mobile app

[cspcrx]

16.9 is all I have seen listed

[Morritse]

So. I am fairly certain the gague represents 15 gallons. Took 14.3 gallons to fill at 10 miles of range.