Low fuel light

[bsp]

This may seem the mother of all stupid questions to some of you guys so I'll endure the flaming but when the low fuel light with that marvelous little ping goes on on my 2005 Golf GLS TDI how much fuel is really left in the tank? I knew how much play I had with my old Rabbit diesel but I'm not sure with this car.

 

[BigI]

I my Jetta I have gone as far as 100km before fill up during summer, in winter i would not go more than 80 km.

 

[mnoeltne]

It's supposed to have 1.9 gallons left when the light comes on, but like any fuel gauge or low fuel light it could be different on your car so don't try to depend on getting down to the last .1 gallons. I usually figure on 50 to 60 miles just to be safe.

If you want it to be extremely accurate, it is adjustable with VAG-COM. I believe there is a post somewhere that tells how to calibrate it.

 

[bsp]

thanks...at least it gives me an idea

 

[mrGutWrench]

__. On my car, I've had the fuel light come on within a mile or so of a station that I wanted to buy fuel from. On each of those occasions, I've been able to put in 14.9 gallons. Since most people who have run their tanks dry (on purpose or by accident) have found that it takes 17.0 gallons or very close to it to fill, that implies that I have about 2.1 gallons when the light comes on -- as mentioned above, the book says 1.9 gallons so mine is pretty close to book.

__. But the light is adjustable, using the "VAG-Com" computer program. In my mind, anything that's adjustable is capable of being mid-adjusted, so your light's setting could vary from others -- you'll just have to experiment a little to see.

__. All the capacities mentioned above are with a fully-vented or "ventectomied" fill, with liquid fuel visible at the fuel filler neck/fuel cap area. You are "venting" aren't you?
'

 

[bsp]

Yep-first thing I did after joining this forum

 

[Jetta_Pilot]

My manual states that the reserve when the light comes on is 11 litres or 2.9 US gallons regardless how much you can put into the tank. The reserve has nothing to do whatsoever whether you can fill it up to the neck.
It is what is left in the tank at that time.

 

[mrGutWrench]

Yep-first thing I did after joining this forum

__. OK, then I'd suggest that you get a good fill (when you have time, fill until the foam is gone and there's liquid fuel right up to the filler neck). Then drive until the light comes on and fill again the same way. Subtract the amount of fuel that you put in the second time from 17.0. That will give you a reasonable estimate of the amount of fuel that's remaining when the light comes on.

__. But don't forget that this is an estimate -- and, as I said in the earlier message, the amount can be changed by using the computer-link ("Vag-Com") program. But mine has seemed very consistent over nearly 90K miles -- if I fuel up when the light comes on, it takes 14.9 gallons.

__. A second issue is that I don't really run too far into the light. Running out of fuel on the side of the road can be a BIG thing in these vehicles (you'll need to refill the fuel filter and probably re-prime the injectors -- just what I *DON'T* want to do on the side of the road). I drive 900 miles and refill when the light comes on.
'

 

[mrGutWrench]

My manual states that the reserve when the light comes on is 11 litres or 2.9 US gallons regardless how much you can put into the tank. The reserve has nothing to do whatsoever whether you can fill it up to the neck. It is what is left in the tank at that time.

__. You might want to check your manual again ... mine says that it's 1.9 gallons/US (and 7 liters -- not that I give a flying fart in a whirlwind what the French measurement is).

__. But that doesn't matter. If he's not ventectomied he's going to have a *VERY* hard time in getting a good figure for total fill. If you don't know total fill versus the total tank capacity, he can't accurately estimate what the reserve is __on HIS car__.
'

 

[meganuke]

I go a minimum of 60 miles after the light comes on before I think about refilling. I've gone over 100 miles, but that was a little nerve-wracking.

 

[Variant TDI]

snipped and snapped...

-- if I fuel up when the light comes on, it takes 14.9 gallons -- But don't forget that this is an estimate ---

Refueling exactly at the light gets me 15 gallons, and usually don't have the patience to wait for all the foam to go down. So that lends credence to the 'estimate' thing, since I fit more fuel in at the light as GutWrench, and I could fit more if I wanted.

And in my experience, the fuel light is very variable as to when it comes on, being very sensitive to steep grades. I put a field in my fuel mileage spreadsheet that allows me to enter when the light comes on, and calculates how much is left based on tank economy and an assumed 17 gallon total.

It hovers pretty steadily aroud 1.9 gallons, but has claimed as high as 2.6 gallons.


God only knows why the TDI didn't get a MAF display when my VR6 and my wife's friggen minivan both have MPG displays that are accurate enough to run the tank to within 10 miles of empty without much drama.

 

[bsp]

Thanks guys....just to be clear, I wasn't going to be stupid enough to run the car down to fumes, but rather wanted to know what my basic safety margin was before I started to panic. Real world comments/suggestions here in addition to what the manual says are helpful as I wasn't expecting perfect specificity on the issue.