# Testing what Low Fuel and Zero Miles Left really means



## UTE (Nov 12, 2011)

Here's my results with reality testing the low fuel indicator, miles left readout and fuel tank capacity of the Beetle when running low on fuel. What I've observed... 

My “low fuel” indicator comes on at precisely 1/8 tank. 

I hit “0 miles left” to refill at exactly the same moment my fuel gauge hits the empty line. 

When I fuel up with the fuel gauge on empty and miles left at 0 it takes 13.3 gallons to fill the tank*. 

From the above I deduce I have 1.2 gallons of fuel left when my vehicle indicates my tank is empty. Cruising the MarkVI forums, this seems to be in line with what others have found (they have our same tank and gauge set up). VW has obviously erred on the side of safety assuming we'll push our luck at some point. 

* Filling up means letting the pump kick off, waiting a moment, and then resuming filling until the pump kicks off again. 

Bill


----------



## KNEWBUG (Sep 13, 2011)

*Fuel tank*

I have also found that when the automatic shut off stops, the tank is not full, add some more until it shuts off again. 






KNEWBUG


----------



## Cadenza_7o (Jan 23, 2001)

For my '01 NB, I've occasionally kept track of how much fuel is left when the low fuel warning light goes on at the red zone (one notch above 0). It's been consistent at 1.9-2.0 gallons. My passengers go nuts when I drive 40-45 miles after the warning. With the needle at 0, there's actually 1 gallon left. It's especially fun when the passengers are kids and I tell them they have to push the car if it runs empty. In the 11 years of ownership, I've yet to run empty. 

:laugh:


----------



## JR Martinez (Feb 25, 2003)

So at 0 miles left I really have 22city/29highway miles left to find a Gas Station? Yeah, my wife will go nuts before that for sure. 

Good to know thanks,


----------



## Cadenza_7o (Jan 23, 2001)

JR Martinez said:


> So at 0 miles left I really have 22city/29highway miles left to find a Gas Station? Yeah, my wife will go nuts before that for sure.
> 
> Good to know thanks,


 JR - the calibration of gas gauges varies from car to car; it doesn't have the accuracy of a Swiss chronometer. You should test your gauge a few times and calculate for the average. 

At the moment the warning light goes on, refill the tank to full within 5 miles. A full tank is 14.5 gallons, minus the refill and you have what's called the reserve amount. Repeat this method a few times and take the average. 

My '01 NB reserve is ~1.9 gallons or about 47.5 miles. To leave room, I never drive more than 40 miles (after the warning light) before refill.


----------



## alpinweiss (Aug 10, 2007)

I hope all of you running near empty have comfortable walking shoes.  

:beer:


----------



## true story (Jun 18, 2007)

KNEWBUG said:


> I have also found that when the automatic shut off stops, the tank is not full, add some more until it shuts off again.
> 
> 
> 
> ...


 
Why? I never understood "topping off." All fuel systems are designed so that when they are "full" there is still a calculated amount left empty to account for expansion of fuel. Granted, if the "full" level is only 90% full, I doubt the fuel will expand 10-12% resulting in a spill, but why risk it? I actually used to fill up only a half tank to get better MPG. I don't get it at all.


----------



## Westhigh76 (Sep 6, 2013)

*Filling up*

I took my 2012, 2.5 down to zero miles left and then filled up at 13.3 gallons...it's funny how they call it 14.5 gallons including 2 gallons in reserve in the owners manual...why don't they just say 14.5...I'm worried about putting in more gas after the first click because the owners manual page is full of warnings not to do so...you will get a full tank after the first click if the car is level or the nose is tilted slightly downward...that's been my experience...


----------



## TypeSH (Jul 11, 2013)

true story said:


> Why? I never understood "topping off." All fuel systems are designed so that when they are "full" there is still a calculated amount left empty to account for expansion of fuel. Granted, if the "full" level is only 90% full, I doubt the fuel will expand 10-12% resulting in a spill, but why risk it? I actually used to fill up only a half tank to get better MPG. I don't get it at all.


Also, worth noting that you risk damaging your evaporative emissions equipment every time you fill past the first auto click-off. You can end up getting liquid gasoline on the charcoal canisters. 

And what's the advantage? You get to fill up in 325 miles instead of 300??


----------



## Rho42 (Feb 8, 2013)

TypeSH said:


> Also, worth noting that you risk damaging your evaporative emissions equipment every time you fill past the first auto click-off. You can end up getting liquid gasoline on the charcoal canisters.
> 
> And what's the advantage? You get to fill up in 325 miles instead of 300??


I think they mean the fuel gauge on the vehicle itself doesn't read full if you only gas it to the first click at the pump.


----------



## IndyTTom (Oct 23, 2007)

Rho42 said:


> I think they mean the fuel gauge on the vehicle itself doesn't read full if you only gas it to the first click at the pump.


Mine always does, besides it is not advisable to top of your gas tank on modern cars it can cause serious damage to emission systems when overfilled. Same with running your tank too low. It can lead to premature fuel pump failure and in the winter time to moisture build up and freeze your fuel line. 

Why take the chance.


----------

