True tank capacity...

[djmatte]

I recently ran my TDi beetle down to damn near nothing. Gauge said I had 5 miles left and it was right at the bottom of the reserve tank line. According to the documentation, this car has a 14.5 gallon tank, 2 of which make up the reserve. But I went to fill up and got up to 12.8 when the pump clicked. Are they that far off in their documentation?! It makes more sense because if I got 560 miles on 14.5 gallons, then my gas mileage is WAY lower than what my gauge is telling me. If its closer to 13 then its more on par. Not sure if theres a difference between the tdi beetles and the gas ones either. Let me know what you all see.

[Beets]

My 2012 2.5 doesn't seem to be that far off. I haven't run down much below 1/4 tank, and have put right around 12 gallons in at that point.

[vdub10golf]

Might be a fuel sensor issue? I know with mine (Turbo) the needle wouldn't go up to "1" because the sensor wouldn't let it completely fill the tank up. Is your needle showing full or just under full right after you fill up?

[eunos94]

I've discovered that at the 'first click' I can still add up to 3 gallons of fuel depending on how much foam filling up caused to accumulate. My bug on it's first and second fill would not show full but after topping off it showed full and took 13.8 gallons from just above 0. My mpg and distance to empty are also much less optimistic (nearly accurate) now that I'm fully topping off too.

[LEBlackRob]

Might be a fuel sensor issue? I know with mine (Turbo) the needle wouldn't go up to "1" because the sensor wouldn't let it completely fill the tank up. Is your needle showing full or just under full right after you fill up?

Yea I had this issue seemed to go away, as I drove it. Now it has gone straight to full with the last 2 tanks of fuel. I will probably fill her up today so we will see if she makes it to 3 tanks with gauge working correctly.

[djmatte]

Mine shows full every time i fill to the first click. maybe i can technically squeeze more out next time.

[LEBlackRob]

Yea seems like it fixed it's self go Volkswagen.

[djmatte]

Soo here's something interesting. As I was driving home, I was running low on gas. I get to a gas station with 0 miles left on my indicator and my line down to E on the line. This station had no diesel. Car was still running so I drove across ann arbor in stop and go traffic, hit every traffic light, and even saw the line start to dip below the E line with the digital gauge still saying 0 miles left and I never ran out of gas. When I hit the gas station, I put in 2 gallons exactly (know a cheaper place to fill up) and it bumped my gauge past the red "reserve" area and to almost 1/8 a tank. Now per documentation, the reserve tank should be 2 gallons. So I am thinking my gauge may be wrong.

[Beets]

The gauges are likely pessimistic by design. The worst thing possible for a fuel pump is to run dry because the fuel moving through the pump is what cools the electric motor. Run them dry and they overheat and burn up. My Mazda2 I just traded out of was annoyingly calibrated, there was still 1/4 of a tank when the car read 0 miles to empty. I once drove another 103 miles when the car said empty and only put 10.9 gallons in an 11.5 gallon tank. The Beetle, and every other VW, model is likely calibrated to read the same way, with a "reserve" of fuel when the tank reads empty. Perhaps this is what VW means by a 2 gallon reserve? Not sure on that but seems plausible...

[djmatte]

As per the manual, the red is supposed to indicate you are now on your 2gallon reserve. May just need to swing by vw.

[LEBlackRob]

The gauges are likely pessimistic by design. The worst thing possible for a fuel pump is to run dry because the fuel moving through the pump is what cools the electric motor. Run them dry and they overheat and burn up. My Mazda2 I just traded out of was annoyingly calibrated, there was still 1/4 of a tank when the car read 0 miles to empty. I once drove another 103 miles when the car said empty and only put 10.9 gallons in an 11.5 gallon tank. The Beetle, and every other VW, model is likely calibrated to read the same way, with a "reserve" of fuel when the tank reads empty. Perhaps this is what VW means by a 2 gallon reserve? Not sure on that but seems plausible...

This guy is right and trust me you don't want to replace a fuel pump on that car. My last VW was a TDI. If those pumps fail you your looking at around 2g in repair.

[kballard72]

I'm at 5 miles to go now, hope this theory holds true so I can get to the station a mile from work....