[gouravsinha]

Yesterday while i was filling in fuel i got my tank full and then i remembered that the car companies usually recommend not to get your car fuel tank full up to the brim.

After a lot of thinking i still cant figure out what could be the reason. So the questions are

1) Is getting tank full recommended?
2) If not then why?

Thanks

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[Raccoon]

No problem if you tank up till the auto cut-off kicks in. Avoid filling in any more than that. Prevent the pump attendent from doing so, if he attempts to!

Filling more than when the auto cut-off kicks in is not at all recommended as the gap on top is required to avoid spillage.

[ashthedivx]

Best practice is to fill it up till cut-off only, do not fall into prey of making it a round figure.

[white_vdi]

auto cut-off is the way i go about it and no "round figure ho jaega bhaiya"

EDIT : i use a CC for fuel so change is never an issue.

[sammyboy]

I always fill in multiples of Rs500. Find that easier somehow.

[ashthedivx]

Originally Posted by sammyboy

I always fill in multiples of Rs500. Find that easier somehow.

I do a better way, tankful it uptill cut-off and pay by Credit card with exact paisa amount

[f1fan]

I do a tank full to tank full with CC. Hence no issues with rounding off.

[sam003]

Originally Posted by gouravsinha

After a lot of thinking i still cant figure out what could be the reason. So the questions are

1) Is getting tank full recommended?
2) If not then why?

Thanks

I am doing this for long now, to get full tank till cut off. Its saves frequest visit to PP and decent way to calculate FE.

Regarding Companies recommendation for not going for full tank is only to get some extra miles if we have lesser gas in tank which will reduce the overall weight of the car and will help in increasing some miles in FE. I read this in Mahindra site some yrs ago. They even asked to remove 3rd row seat if you are not using it, just to reduce weight nothing else.

[Ravveendrra]

1. What is your Car ?
Skoda Laura

2. Which of the above practices you follow to refill the car ?
I have always filled it till the auto cut off kicks in, then I run it till well into 'reserve'.

3. How much of fuel you generally fill in each time (on average)?
About 50 to 55 litres

4. Why do you feel your practice is good for your car ?
It prevents corrosion of the tank.
Helps maintain proper ratio and mixing if you are adding additives to the fuel.
Enables me to stick to one or two reliable bunks.
Saves me time.

Some thoughts on Question#4:
1. In case of FULL TANK the prolong storage causes Octane Value of the Petrol to diminish. The full tank will also reduce work of the fuel pump and keep it cool. The extra fuel will also add on Weight to Vehicle which will decrease your Fuel Effeciency.

I have not really found any appreciable difference in handling due to the weight of the fuel. There is absolutely no difference to the FE. If anything, the extra stopping and starting required to fill in the fuel more number of times will kill your FE!

I need to check on the 'octane value' of the fuel diminishing over time. But I dont think it will diminish in the two or three weeks that I take to run through one tank full.

I had noticed that the mechanical fuel pumps in the older cars worked better with fuel at full level; at one time my old Jawa (gravity flow) would flood if the tank was full! It does not seem to make too much of a difference with the newer electronic pumps.

2. On the other hand, in case of EMPTY TANK, the petrol tank empty the water vapour from the fuel will corrode the metallic tank and may result in a fuel leakage in future (as it hapenned to me).

That is a problem that I have noticed in other vehicles who never had their tanks full. Less fuel also increases the chances of accidentally getting an air lock (murder in the Diesel engines and perhaps also the MPFi ones).

Cheers,

[Jaggu]

Originally Posted by gouravsinha

1) Is getting tank full recommended?
2) If not then why?

Depends on what is full for you, if you stop at first or second cut off, its should be fine since it will fill up only the main tank. Less vapor loss, if metal tank then will help avoid corrosion etc being the reason.

If tank full mean filling up to brim then NO from me, coz it fills up the overflow tank/circuit which is there to collect the overflow in case of a emergency situation like accident/turtle turn etc

EDIT: What car manual referring to is "filling up to the brim"

[KSM-Vtec]

Well yes filling till the first or second cutoff is ok...but anything more than that can lead to problems with the fuel pump(due to overload), back flow into the overflow pipe.

[Narencar]

I am having santro and always used to fill the tank until cut off and do the payment by credit card.
After cut off the tank is always having the capacity of 2-3 ltrs more to fill.

Save fuel...

[Modifiedsachin]

Hi there,

My zen gets a Full tank (I think the tank is of 35L) every week (60km everyday) so app I get an fuel efficiency of 10.2, but since last few months, I am observing a strange problem.

I ask the pump guy to make tank full (ULP) & pay by CC, but after my first ridr to office (say 30 kilometers) the car starts to take load, with only 2 persons (me & my friend) the accelerator needs to be pressed hard to get to even speeds of 40.

After few checks one day someone told me not to tighten the tank lead & I loosened it and then started the car & to best of my surprice the car started running smooth again.

Now every time I ask the guy to keep it lose but the problem persists, after first run I have to open the lead (when a air pressure is clearly seen, the air releases as if I am openinga cold drink bottel) and then re fit it (loose) to get the car in normal operation.

My friend who owns a guarage suggested that I can get a hole drilled (very fine one) so that air gets the way. But some how affraid of that.

Is my pump guy filling my overflow tank as well? or the lead is problemetic?

[jack7]

1. What is your Car ?
OHC

2. Which of the above practices you follow to refill the car ?
I fill it until auto cut off and ensure I make a refill every time the fuel indicator comes to the middle. I also ensure I fill up in the mornings and look around for fuel tankers pumping fuel into the gas stations tanks.

3. How much of fuel you generally fill in each time (on average)?
About 20 to 22 liters

4. Why do you feel your practice is good for your car ?
It prevents corrosion of the tank.
Ensuring you fill in the mornings gets you good fuel density.
Not allowing the fuel indicator to go below the middle gives limited space for evaporation in the cars fuel tank
If a fuel tanker is filling up the tanks of the gas station then the fuel quality could probably be a little bad imho.

[Prowler]

Modifiedsachin Your filler cap's vent is probably clogged. Clean that and you will not have to drill extra hole in it. When the tank is not vented or the vent is blocked, the fuel pump has to work harder to supply the fuel to the engine.

I noticed another odd thing with my Tata Safari earlier. Every time the fuel level comes down, the engine will die out. I can see that there is enough fuel on the meter. Once I shut down the AC, the car will start normally and run normally.