ventsectomy: is it okay just to let the pump click?

ecala001

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is it okay to just let the pump click? I've read countless threads but many say to fill more till you see it. If I just fill till I hear the click is that fine?
 

IndigoBlueWagon

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If you stop when the pump clicks off you're leaving room in the tank. I run the pump until it clicks off, then run the pump slowly as the foam settles and I can see clear fuel at the top of the filler neck. If you wait a moment the vent may also let some air out and the fuel level will drop, and you can top up again. I think this is the best way to get both the most fuel in the tank and a consistent fill.
 

jokila

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Consistency is key. Some pumps are more sensitive to the back up of fuel and sometimes there is more foam depending on the angle of the nozzle in the neck.

Get it to the top.
 

Lightflyer1

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If all you want to do is fill the car and drive, then yes that is okay. If you want to try and accurately record your fuel fills and economy then filling it to the brim is more consistent. But over time just fill and go also is quite close when you are looking at averages.
 

ecala001

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03 golf
will letting it click by itself basically have the same amount as if I did not do the ventsectomy?
 

akjdouglass

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If all you want to do is fill the car and drive, then yes that is okay. If you want to try and accurately record your fuel fills and economy then filling it to the brim is more consistent. But over time just fill and go also is quite close when you are looking at averages.
+1 to this. Inconsistent fueling will cause individual tank mpg numbers to be off somewhat, but your average mpg results over time become more and more accurate.

My cars are MKVI so I stop after one click. If I had a ventectomy, I'd top it off every time simply to get the most miles possible out of every tank.
 

bigsexyTDI

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I would venture to say that with a ventectomy and the pump set on the first click, you would anecdotally fill more than non-vented and set to the fastest pump setting. How much more is the question.

But the ultimate consensus is, that if you were just going to fill to the click, then the ventectomy was probably for naught.
 

IndigoBlueWagon

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The ventectomy only adds small capacity and allows consistancy from one fill up to the next.
I don't call 2+ gallons added to a 14.5 gallon tank small. Most I've added to my Wagon is 16.9 gallons. I was pretty anxious, however. At 50 MPG that's 140+ miles. Not nothing.
 

Rrusse11

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I hit the click, and then know there's upwards of another 2 gallons to be gently squeezed in. Pumps and nozzle flow vary,
it is more consistent. Not that I pay too much attention or keep any accurate record, and I fill when my gauge hits a 1/4,
or see a good price. Ekeing out a single tankful of fuel strikes me as a bit absurd, FE is the same, and having had vehicles with dodgey gauges, I fill up with LOTS left in the tank.
 

jokila

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I hit the click, and then know there's upwards of another 2 gallons to be gently squeezed in. Pumps and nozzle flow vary,
it is more consistent. Not that I pay too much attention or keep any accurate record, and I fill when my gauge hits a 1/4,
or see a good price. Ekeing out a single tankful of fuel strikes me as a bit absurd, FE is the same, and having had vehicles with dodgey gauges, I fill up with LOTS left in the tank.
It's about 80 to 100 miles more distance per tank before the next fillup, even at your fillup point on the gauge. It's not absurd to want to cram as much fuel as you can.

Small is relative. I didn't know exactly what it was but didn't mean to imply it was 2 ounces or anything.
Not to dogpile on you, but it's about 15% more volume, so not small.
 

Lightflyer1

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It's about 80 to 100 miles more distance per tank before the next fillup, even at your fillup point on the gauge. It's not absurd to want to cram as much fuel as you can.



Not to dogpile on you, but it's about 15% more volume, so not small.
Like I said, not small to you but it is to me. I define small as 25% or less. ;)
 

IndigoBlueWagon

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Like I said, not small to you but it is to me. I define small as 25% or less. ;)
Well that's arbitrary. :cool: For me it allows me to easily go 700 miles on every tank, and 800 on more than a few. It's one of the things I love about these cars.
 

Rrusse11

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"It's not absurd to want to cram as much fuel as you can. " Jokila

Oh I agree, it's not absurd to want to fill the tank completely, my point is that wringing the last 100 miles out of a tank,
running the risk of running out of fuel, is IMO, a bit silly. Personally I don't want to be by the side of the road bleeding
the fuel system. You don't gain any fuel economy, so I just fill up one more time every 1/2 dozen fuel stops.
But to each his own,,,,,,,,,,,
 

Mongler98

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Just fill it up. Drive more. Focus on good driving techniques vs how much fuel you can shove in your back pocket
But no. Just fill it up till the foam is gone and you can see the fuel to a specific mark.
 

IndigoBlueWagon

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I always drive my car a bit after the low fuel light comes on. Done that with all my cars. Last time I recall running out of fuel was in my '57 Bug that had no fuel gauge and a non-working reserve tank. I did it on purpose to find out if the reserve worked. It didn't.
 

MikePA

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So there's no harm in doing this? This is my first diesel, and with Gas cars, you'd be over-flowing into the recovery canister which I guess doesn't exist on these. I've never heard this method endorsed before.
 

IndigoBlueWagon

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You actually are filling the expansion area of the fuel tank. Diesel doesn't expand, so you don't need it. And VW used to use the same fuel tanks for gas and diesel engines. The ventectomy (or pushing down the button on the side if the filler) allows that expansion tank to fill. Totally harmless. Can't do it on MKV and later TDIs.
 

jokila

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"It's not absurd to want to cram as much fuel as you can. " Jokila

Oh I agree, it's not absurd to want to fill the tank completely, my point is that wringing the last 100 miles out of a tank,
running the risk of running out of fuel, is IMO, a bit silly. Personally I don't want to be by the side of the road bleeding
the fuel system. You don't gain any fuel economy, so I just fill up one more time every 1/2 dozen fuel stops.
But to each his own,,,,,,,,,,,
Ventectomy isn't about FE. I am not sure why you keep tying that point into your comments. You will still have the same 100 miles of tank left regardless if you vent. If you vent, you will just take longer until you get to your arbitrary point of filling up. I think you are confusing how long people go before filling up with venting.

The point is you can go a longer distance vis a vis without a vented tank. I average about 660when the light comes on. I have about 2 gallons left in the tank at that point. I have lots of time to find a fuel station. Lots!

It's actually less stressful to know you have a longer max distance. Maybe that's one more day of driving for some, but it's convenience.
 

Mongler98

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There are 2 types of people in this world.
Those who fill up at 1/4 tank left
And those who run put every drop and have to prime the engine
 

Tdijarhead

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Venting for me is about a two gallon difference as others have said. The difference between going about 700 miles per tank and going 770 to 810 miles per tank.
 

MikePA

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Well this was real intriguing until you told me it doesn't work for my car. LOL
 

IndigoBlueWagon

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Here's IBW's Fuelly summary. As you can see I didn't start this until I'd had the car a while, but I've been religious about tracking every fill for the last 200K+ miles

If you divide the total miles by the number of fuel logs you get an average of 715 miles per tank. Couldn't have done it without venting, filling until I see clear fuel, and running until after the low fuel light comes on, tank after tank. And I've never run out of fuel in this car. The average fill up was 15.2 gallons per tank.

Also, keep in mind that for the first 80K or so of this log I was running big fuel and an aggressive tune. My FE has improved since the engine swap. But that's why the average FE is on the low side.
 

jokila

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Here's IBW's Fuelly summary. As you can see I didn't start this until I'd had the car a while, but I've been religious about tracking every fill for the last 200K+ miles

If you divide the total miles by the number of fuel logs you get an average of 715 miles per tank. Couldn't have done it without venting, filling until I see clear fuel, and running until after the low fuel light comes on, tank after tank. And I've never run out of fuel in this car. The average fill up was 15.2 gallons per tank.

Also, keep in mind that for the first 80K or so of this log I was running big fuel and an aggressive tune. My FE has improved since the engine swap. But that's why the average FE is on the low side.
Just flip your phone to landscape view and it will show you your average miles per tank.

I am about to hit a milestone with Fuelly with my next tank.
 
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