Fuel wonders

[primekart]

"We discovered that we can increase the fuel tank capacity of the Beezer by
pushing on the button situated on the right of the mouth.

You must do that when you reload your tank. The gain is about 5/10 liters. "


Hi Flapper,

Have you seen that massage in Ibiza Forum?
I have looked into the fuel filling neck and there is a botton in there! I could not find any mentioning to that in the owner's manual! What is it for? I have noticed that the botton is pushed down as I close the fuel cap tight, I could here the clicking sound of the botton. Something to do with the pressurising of the tank for the Motronic system?

[primekart]

From tdiclub.com , here is the answer to my question!!



In the filler neck of the tank, in the 9 o’clock position is a
little black button. This is a vent relief valve that can be pushed with the fuel nozzle when “topping up” the tank to squeeze in a few extra litres. The button is normally activated when the fuel cap is screwed on. Note that the OBDII system on North
American models detects if the fuel cap is not properly tightened (via tank pressuriza-tion) and will set an error code (fuel vapor is escaping to the atmosphere).
It should be noted that the vent valve is to prevent topping up. Overfilling the tank could cause heat expansion to push fuel up the neck and create a spill. The vent keeps an amount of air in the tank until the cap is returned. The air in the tank moves up
into the neck as the fuel in the neck moves down into the tank. Any expansion could now burp air instead of fuel.
Topping up using the vent valve should be done only when the car will be driven long enough to consume a few litres of fuel before stop-ping the engine. Don’t top off with the vent pressed and then park in the sun. For accurate fuel mileage calculations always use the same technique when refueling Either always “top up” by venting the expansion chamber, or never vent and stop
refilling when the dispensing nozzle shuts off. That extra half gallon or two liters of fuel squeezed into the expansion chamber will make the trip consumption appear higher if this venting technique is used intermittently.