[R2D2]

Originally Posted by Gansan

I have noticed a latest problem with the fuel gauge of my Alto after the last refill. I always fill up to the brim. The indicator will show F till about 80 KM or so, and then start gradually moving down.

Gansan, when you say you fill to the 'brim', what is that supposed to mean? Is it when the pump automatically shuts off or is it when the attendant or yourself decide that the tank is full based on how much fuel has been pumped in?

The sender unit in the fuel tank is calibrated to move with a certain volume and level of fuel in the tank. If you are overfilling there is a chance that the float will be stuck at the full position till the fuel level drops to the maximum calibrated level. Have you noticed this at a particular petrol station or is it across different petrol stations? Please remember that the back pressure 'sensor ' in petrol station fuel pumps are not very accurate.

[Gansan]

^^I make them fill after the auto cut-off till a few inches below the lid, and shake the car a few times to remove any air. I have noticed this problem for the first time in three years, and my car always goes to a particular nozzle at the Shell station near my home. I never fill anywhere else.

@Sutripta
The gauge still shows more quantity than what is in the tank, though it has since moved down from the F mark.

[R2D2]

Originally Posted by Gansan

^^I make them fill after the auto cut-off till a few inches below the lid, and shake the car a few times to remove any air. I have noticed this problem for the first time in three years, and my car always goes to a particular nozzle at the Shell station near my home. I never fill anywhere else.

Over filling is not recommended. Stop filling when the nozzle deactivates or switches off. Remember that excess fuel is drained off thru an overflow pipe and onto the road. It is a waste of money.

Whilst travelling in KA, I had the experience of watching the fuel station filling my car's petrol tank to the point it nearly overflowed from the fuel tank filler. Unfortunately the pump didn't switch off automatically. A bit of fuel overflowed. I yelled at the pump attendant and asked him if he was filling a truck. I got a sheepish grin and a 'sorry saar' in return.

Obviously I tried bumping the car a bit to help settle the fuel to no avail. The tank was 'filled to the brim'. Sadly I could smell fuel in the cabin for at least 60 kms afterwards even when driving at highway speeds of 120-130 kmph. That smell is the fuel that was being drained. At nearly Rs 80/litre I wasn't a happy chap.

So, go easy..when the pump switches off, stop filling and check if your wayward fuel gauge behaves normally.

[Gansan]

Originally Posted by R2D2

Over filling is not recommended. Stop filling when the nozzle deactivates or switches off. Remember that excess fuel is drained off thru an overflow pipe and onto the road. It is a waste of money.

I did not know this. Where is this tube located? I never see any petrol dripping out like this. Because, after filling to the brim, I simply go home (just 1 KM away from Shell) and park the car. Never noticed any petrol smell even.

I fill till a visual level to check on mileage.

[R2D2]

Originally Posted by Gansan

I did not know this. Where is this tube located? I never see any petrol dripping out like this. Because, after filling to the brim, I simply go home (just 1 KM away from Shell) and park the car. Never noticed any petrol smell even.

I fill till a visual level to check on mileage.

Gansan, I am not saying that fuel is dripping out in your particular case. That may or may not be the case. It sure happened with me.

Also automatic shutoff is there for a reason - preventing wastage of fuel and preventing fuel fumes from escaping into the enviroment i.e. eco consciousness. Most States in US are taking this seriously courtesy a mandate by the US EPA.

This is a transparent tube (at least on my car) and is located near the mouth of the filler hose. This is the black hose that connects your fuel tank with the filler mouth.

I didn't see petrol dripping out as the drain hose is concealed and most of it would leak out when the vehicle is moving (petrol sloshing in the tank/filler pipe) or vented as gasoline vapour. But I could smell petrol inside the cabin - which has NEVER happened in my car before. With AC switched on fuel vapours in the closed cabin can be unhealthy. Like cooking gas, smelling petrol fumes is a sure sign of a leak however minor.

Check mileage check full tank to full tank with the auto shut off method. This is easier since you use the same nozzle at the same petrol station. If there is fuel leakage preventing it may help get better mileage.

[Sutripta]

Originally Posted by Gansan

@Sutripta
The gauge still shows more quantity than what is in the tank, though it has since moved down from the F mark.

No, was wanting to know behaviour of Temp gauge.

Regards
Sutripta

[Gansan]

^^Temp gauge is functioning normally. So do all the dash indicator lamps.

I completed the 3 year service yesterday. This problem was not attended as they wanted me to observe the gauge for two more refills. Electrical fault has been ruled out.

[Gansan]

Originally Posted by Aroy

For all you know, your Alto is responding to enhanced petrol cost by going frugal

Aroy, I think you were right after all! I completed the 3rd year service a couple of days ago. The service supervisor told me to fill fuel a couple of times more and observe the gauge before we touch the fuel tank, since this has happened for the first time. I agreed.

The trip meter was at 309 KM and the gauge was slightly above half tank mark when I went to Shell today. I filled super unleaded till the brim, the car took in 15.780 litres, and would take no more. The mileage was a fantastic 19.58 KMPL! This is very close to my usual highway mileage of ~ 21 KMPL. No idea how this happened. Perhaps I drove mostly during traffic free hours which almost replicated highway conditions! So the gauge showing half tank was right after all!

Then I set the trip meter to zero, went for a 50 KM "Gansan patented mileage test" on the Bangalore highway (which I routinely do after every service) and went back to Shell for a top-up. The result was 25+ KMPL, as always!

Anyway I will observe it for a couple of more refills during a planned highway trip before deciding whether the gauge needs attention.

[Aroy]

Originally Posted by Gansan

Aroy, I think you were right after all! I completed the 3rd year service a couple of days ago. The service supervisor told me to fill fuel a couple of times more and observe the gauge before we touch the fuel tank, since this has happened for the first time. I agreed.

The trip meter was at 309 KM and the gauge was slightly above half tank mark when I went to Shell today. I filled super unleaded till the brim, the car took in 15.780 litres, and would take no more. The mileage was a fantastic 19.58 KMPL! This is very close to my usual highway mileage of ~ 21 KMPL. No idea how this happened. Perhaps I drove mostly during traffic free hours which almost replicated highway conditions! So the gauge showing half tank was right after all!

Then I set the trip meter to zero, went for a 50 KM "Gansan patented mileage test" on the Bangalore highway (which I routinely do after every service) and went back to Shell for a top-up. The result was 25+ KMPL, as always!

Anyway I will observe it for a couple of more refills during a planned highway trip before deciding whether the gauge needs attention.

so some one has responded to enhanced fuel prices.

My K10 is now giving me 10.5. Of course I drive in the colony with median trip length of 1km and rarely cross third gear. I hope my car will get inspired by yours and gives me that fantastic average.

[R2D2]

Originally Posted by Gansan

Then I set the trip meter to zero, went for a 50 KM "Gansan patented mileage test" on the Bangalore highway (which I routinely do after every service) and went back to Shell for a top-up. The result was 25+ KMPL, as always!.

Gansan, 25 kmpl is fabulous. I've also known Altos to give ~18-20 in city and 21-22 on the highway. Can you please detail your patented mileage test for the benefit of other car, especially Alto/800 owners?

Originally Posted by Gansan

Anyway I will observe it for a couple of more refills during a planned highway trip before deciding whether the gauge needs attention.

I do not believe there's a fault with your fuel gauge.

As mentioned before if during 2 of the refills you adopt the auto cut off method at the same nozzle it may provide you with a far more accurate fuel consumption figure. Added to the fact that you avoid excess overflow. Just a suggestion mind you.

[Gansan]

Originally Posted by R2D2

Gansan, 25 kmpl is fabulous. I've also known Altos to give ~18-20 in city and 21-22 on the highway. Can you please detail your patented mileage test for the benefit of other car, especially Alto/800 owners?

The best I have obtained in the city prior to this was 17 KMPL once, and the worst 12 KMPL! It is usually around 14 - 15 KMPL. The best in the highway (not counting the mileage test) has been 22.5.

The "patent" mileage test can be done for any car as follows:

1. Select a good fuel station. It will be ideal if you can enter the highway quickly from here, without getting struck in traffic.

2. Select a traffic free hour on a holiday. I always go at 8.00 AM on a Sunday!

3. Fill petrol by auto cut off method. After cut off, let them fill manually (slowly) till an inch or two below the brim. Wait a few seconds, give the car a couple of shakes. If the fuel tank "burps" and the level goes down, fill again. The level will usually stay put after this.

4. Check and set correct air pressure. No luggage. Go alone or take just one companion. Set trip meter to zero, start and enter the highway asap. Drive freely at 70 - 80 KPH, maintaining top gear for maximum duration. Keep AC on for 10 KM and off for 10 KM, alternatively. But do not roll down windows. After 25 KM, take a U turn and go back to same fuel station, same nozzle.

5. Fill petrol again as per step three. Now calculate FE. This will be our car's best FE, under the most ideal conditions. Can't be replicated in day to day driving, naturally. But if we do this once after every service, it shows there is nothing wrong with the car! Thereafter we need not bother about everyday FE figures, which will vary according to traffic conditions.

Filling petrol till a visual level gives better accuracy to the calculation. If done from auto cut-off to auto-cut off, I feel the average of three such tests will be a better bet.

[R2D2]

Originally Posted by Gansan

The best I have obtained in the city prior to this was 17 KMPL once, and the worst 12 KMPL! It is usually around 14 - 15 KMPL. The best in the highway (not counting the mileage test) has been 22.5.

The "patent" mileage test can be done for any car as follows:

1. Select a good fuel station. It will be ideal if you can enter the highway quickly from here, without getting struck in traffic.

2. Select a traffic free hour on a holiday. I always go at 8.00 AM on a Sunday!

3. Fill petrol by auto cut off method. After cut off, let them fill manually (slowly) till an inch or two below the brim. Wait a few seconds, give the car a couple of shakes. If the fuel tank "burps" and the level goes down, fill again. The level will usually stay put after this.

4. Check and set correct air pressure. No luggage. Go alone or take just one companion. Set trip meter to zero, start and enter the highway asap. Drive freely at 70 - 80 KPH, maintaining top gear for maximum duration. Keep AC on for 10 KM and off for 10 KM, alternatively. But do not roll down windows. After 25 KM, take a U turn and go back to same fuel station, same nozzle.

5. Fill petrol again as per step three. Now calculate FE. This will be our car's best FE, under the most ideal conditions. Can't be replicated in day to day driving, naturally. But if we do this once after every service, it shows there is nothing wrong with the car! Thereafter we need not bother about everyday FE figures, which will vary according to traffic conditions.

Filling petrol till a visual level gives better accuracy to the calculation. If done from auto cut-off to auto-cut off, I feel the average of three such tests will be a better bet.

May I suggest 2 things here Gansan -

1) Some parts of Point # 4 should be point #1. For e.g. the air pressure is the 1st thing that needs to be checked. Rest follows in a logical sequence.

2) I am of the humble opinion that machines are more often than not, more accurate whilst judging the quantity of fuel. So auto cut off to auto cut off with the same nozzle is more accurate than peering down the throat of your fuel tank to ascertain fuel levels.

[swarnava.m]

Originally Posted by R2D2

Gansan, I am not saying that fuel is dripping out in your particular case. That may or may not be the case. It sure happened with me.

Also automatic shutoff is there for a reason - preventing wastage of fuel and preventing fuel fumes from escaping into the enviroment i.e. eco consciousness. Most States in US are taking this seriously courtesy a mandate by the US EPA.

This is a transparent tube (at least on my car) and is located near the mouth of the filler hose. This is the black hose that connects your fuel tank with the filler mouth.

I didn't see petrol dripping out as the drain hose is concealed and most of it would leak out when the vehicle is moving (petrol sloshing in the tank/filler pipe) or vented as gasoline vapour. But I could smell petrol inside the cabin - which has NEVER happened in my car before. With AC switched on fuel vapours in the closed cabin can be unhealthy. Like cooking gas, smelling petrol fumes is a sure sign of a leak however minor.

Check mileage check full tank to full tank with the auto shut off method. This is easier since you use the same nozzle at the same petrol station. If there is fuel leakage preventing it may help get better mileage.

So this means that if I stop filling at the auto cut off point, my tank is holding the exact capacity of 37 litres right? And this means that by filling it upto the brim, I was actually filling more than the max capacity?

[R2D2]

Originally Posted by swarnava.m

So this means that if I stop filling at the auto cut off point, my tank is holding the exact capacity of 37 litres right?

Not really mate. The auto cut off happens at different points and varies from nozzle to nozzle even on the same petrol vending machine, not to speak about differences in petrol stations as well.


So it is best to go to one trusted petrol pump and fill at a particular nozzle as much as possible to maintain consistency between fills.


I hasten to add that auto cut off is inconsistent at best. I know of nozzles where auto cut off doesn't work where I instruct the pump attendant to shut off the flow when I 'hear' the petrol rising (sound changes like when you are filling a bottle with water) and my knowledge of how much fuel will be required based on the position of the dashboard fuel gauge. I do NOT under any circumstances allow the attendant to fill the tank to the brim though they alway try to do so. This throws a further measure of inaccuracy into the fuel efficiency calculation.

Originally Posted by swarnava.m

And this means that by filling it upto the brim, I was actually filling more than the max capacity?

If you were filling it right to the point where you can see the fuel by looking into the filler hole, then yes there's a good chance you are overfilling. Excess fuel is drained off by a concealed pipe. Remember that the tank is required to 'breathe' in order to maintain the flow of fuel. So you must keep the breather hole clean. Overfilling can also block the breather hole.

The strangest thing is that I only see this 'phenomenon' of filling the tank till the fuel overflows in this country. Truly it happens only in India. .

In most countries in the West or SE Asia/Japan etc, owners just stop when the pump auto cuts off. Any extra fuel required for say long distance trips is filled into a jerry can.

[swarnava.m]

Originally Posted by R2D2

Not really mate. The auto cut off happens at different points and varies from nozzle to nozzle even on the same petrol vending machine, not to speak about differences in petrol stations as well.


So it is best to go to one trusted petrol pump and fill at a particular nozzle as much as possible to maintain consistency between fills.

Oh ok.. I was under the impression that the auto cut off is consistent to the vehicle irrespective of the nozzle or the gas stations. Well I guess this clears it up then..

Originally Posted by R2D2

The strangest thing is that I only see this 'phenomenon' of filling the tank till the fuel overflows in this country. Truly it happens only in India. .

Absolutely true. I always fill at the same nozzle at the same station. In fact I was not aware of the fact that filling to the brim is a bad idea, and always used to do so. However, after reading your post a few days back, last time I went for a tank up, I asked him to stop at auto cut off, and he was surprised that I did not let him fill to the brim. I am sure the attendant thinks it is recommended practice to fill to the brim, only since EVERYBODY (including myself) does that!!