How effective is the auto-cut mechanism of the fuel service stations?

johnda · 5th November 2008, 13:02

A good way to keep your head clear of - 'do i have a tank full?' is to fill in liters. That's what I do, when I touch E and go a lil on the red, I fill 40lts so then there is no issues with auto cut off and I have an idea of how much fuel I put. I hope i'm making sense. Ofcourse what I said is not going to be possible if only a little fuel was used and you want to fill it till it spills.

Ricky_63 · 5th November 2008, 18:28

The best way to make the auto cut "really work" is to let the tank fill at the "slowest" setting on the dispenser. Unfortunately that seldom happens, as the attendants usually use the "fastest" mode, hence the froth build up & pre-mature cutoff !!

I usually try to stand on their heads & make them use the slowest mode to their utter dislike (they save some fuel if they use the fastest mode)

Cheers

sanjz · 4th February 2009, 08:55

in my opinion the auto cut off feature is just a safety device to prevent the wastage of precious fuel from spilling.This is in no way an indication that the tank is full to the brim. Infact if the attendant puts the auto cut off at the highest rating there are chances that it will cut off even before the tank is full, owing to foaming and the air rushing out of the pipe.My car genrally takes a good 7 to 8 lts more after auto cutof. The best way to calculate the FE would be to ask the A.S.S. guys to perform the litre bottle test which is indeed a very accurate measure of the FE.

Happy driving !

supremeBaleno · 16th February 2009, 15:26

I used to be a firm believer in the auto-cutoff way of measuring FE because the dispenser (at the HP bunk where I fuel regularly) used to always cut off in a predictable way. But then just once, it cut off much before expected, which I knew was not correct - the FE was too good to be true. Since then I am a bit sceptic about the whole thing.

But then why the need to measure FE on EVERY fill ? I do it only once in a while - maybe once in a year or so. Rest of the time, the practice is to fuel-up for Rs2000 when the indicator hits E. At current fuel rate of 44.24 per litre, it gets me 45litres of fuel. Tank capacity is 51litres and with fuelgauge at E, I expect atleast 2 litres of fuel to be in tank. So, there is space for atleast 4-5 litres more. But having read that filling to the brim is not good for various reasons, I leave it at that.

supremeBaleno · 16th February 2009, 18:51

@Gaurav, you would get your answer in your car manual itself. Atleast for Maruti cars, the manual says you should not fill to the brim. Reason given by them is :

"The fuel tank has an air space to allow for fuel expansion in hot weather. If you continue to add fuel after the filler nozzle has automatically shut off or an initial blowback occurs, the air chamber will become full. Exposure to heat when fully fuelled in this manner will result in leakage due to fuel expansion. To prevent such fuel leakage, stop filling after the filler nozzle has automatically shut off, or when using an alternative non-automatic system, initial vent blowback occurs."

Apart from the above, any fuel spillover can damage the paint of your car.

Perakath · 27th March 2009, 14:34

Quote:

Originally Posted by sanjz

My car genrally takes a good 7 to 8 lts more after auto cutof. The best way to calculate the FE would be to ask the A.S.S. guys to perform the litre bottle test which is indeed a very accurate measure of the FE.

I've never heard of this test-- could you elaborate please?

Quote:

Originally Posted by supremeBaleno

@Gaurav, you would get your answer in your car manual itself. Atleast for Maruti cars, the manual says you should not fill to the brim. Reason given by them is :

"The fuel tank has an air space to allow for fuel expansion in hot weather. If you continue to add fuel after the filler nozzle has automatically shut off or an initial blowback occurs, the air chamber will become full. Exposure to heat when fully fuelled in this manner will result in leakage due to fuel expansion. To prevent such fuel leakage, stop filling after the filler nozzle has automatically shut off, or when using an alternative non-automatic system, initial vent blowback occurs."

Apart from the above, any fuel spillover can damage the paint of your car.

the practice of shaking and filling more fuel seems to be nothing more than ignorance of this. Typical of how most vehicles in our country are treated.

Even if the auto cutoff is not quite the "full" tank, I'm quite happy filling only up to there-- less paisa outlay per visit to the pump!

5th November 2008, 13:02	#31
johnda BHPian Join Date: Aug 2008 Location: Tvla Posts: 394 Thanked: 19 Times View My Garage	A good way to keep your head clear of - 'do i have a tank full?' is to fill in liters. That's what I do, when I touch E and go a lil on the red, I fill 40lts so then there is no issues with auto cut off and I have an idea of how much fuel I put. I hope i'm making sense. Ofcourse what I said is not going to be possible if only a little fuel was used and you want to fill it till it spills.
	() Thanks

5th November 2008, 18:28	#32
Ricky_63 Senior - BHPian Join Date: Dec 2006 Location: Gurgaon Posts: 3,885 Thanked: 518 Times View My Garage	The best way to make the auto cut "really work" is to let the tank fill at the "slowest" setting on the dispenser. Unfortunately that seldom happens, as the attendants usually use the "fastest" mode, hence the froth build up & pre-mature cutoff !! I usually try to stand on their heads & make them use the slowest mode to their utter dislike (they save some fuel if they use the fastest mode) Cheers
	() Thanks

4th February 2009, 08:55	#33
sanjz BHPian Join Date: Nov 2008 Location: Ahmedabad Posts: 130 Thanked: 52 Times View My Garage	in my opinion the auto cut off feature is just a safety device to prevent the wastage of precious fuel from spilling.This is in no way an indication that the tank is full to the brim. Infact if the attendant puts the auto cut off at the highest rating there are chances that it will cut off even before the tank is full, owing to foaming and the air rushing out of the pipe.My car genrally takes a good 7 to 8 lts more after auto cutof. The best way to calculate the FE would be to ask the A.S.S. guys to perform the litre bottle test which is indeed a very accurate measure of the FE. Happy driving !
	() Thanks

16th February 2009, 15:26	#34
supremeBaleno Senior - BHPian Join Date: Dec 2005 Location: Chennai / Kochi Posts: 5,546 Thanked: 2,698 Times View My Garage	I used to be a firm believer in the auto-cutoff way of measuring FE because the dispenser (at the HP bunk where I fuel regularly) used to always cut off in a predictable way. But then just once, it cut off much before expected, which I knew was not correct - the FE was too good to be true. Since then I am a bit sceptic about the whole thing. But then why the need to measure FE on EVERY fill ? I do it only once in a while - maybe once in a year or so. Rest of the time, the practice is to fuel-up for Rs2000 when the indicator hits E. At current fuel rate of 44.24 per litre, it gets me 45litres of fuel. Tank capacity is 51litres and with fuelgauge at E, I expect atleast 2 litres of fuel to be in tank. So, there is space for atleast 4-5 litres more. But having read that filling to the brim is not good for various reasons, I leave it at that. Last edited by supremeBaleno : 16th February 2009 at 15:27.
	() Thanks

16th February 2009, 18:51	#35
supremeBaleno Senior - BHPian Join Date: Dec 2005 Location: Chennai / Kochi Posts: 5,546 Thanked: 2,698 Times View My Garage	@Gaurav, you would get your answer in your car manual itself. Atleast for Maruti cars, the manual says you should not fill to the brim. Reason given by them is : "The fuel tank has an air space to allow for fuel expansion in hot weather. If you continue to add fuel after the filler nozzle has automatically shut off or an initial blowback occurs, the air chamber will become full. Exposure to heat when fully fuelled in this manner will result in leakage due to fuel expansion. To prevent such fuel leakage, stop filling after the filler nozzle has automatically shut off, or when using an alternative non-automatic system, initial vent blowback occurs." Apart from the above, any fuel spillover can damage the paint of your car.
	() Thanks