Petrol stations-is a litre really a litre??

blacklabel · 12-08-2007, 11:13 AM

Gidday all,

Did a few miles across town during the week in my 98AU Futura and ending up topping up at the same different petrol station twice.
Now normally I use BP or Shell in my home neighbourhood and usually chuck in $40 when my fuel needle gets to 1/4.This gets me to 3/4.
No difference between these 2-the price is always the bloody same...and so seems the level in my tank.
But during the week I topped up at Gull,again at 1/4 tank,-as that's my "visual" signal,banged in $40, and hey-I've got my needle sitting at midway between 3/4 and Full! I did this twice,and virtually identical result.
I haven't done a full comparison using the DTE meter,but it has to be a good 30km plus for the same money- I'm obviously getting more bang for my buck at Gull.
Which got me to thinking...how accurate is the caliberation on pumps at service stations-and how could there be such a difference??

**To consolidate my point, it is now sunday- and I thought I'd mow my lawns...(sunday bloody sunday!) So I thought I'd turn it into an excercise.
I took both my 6lt jerry cans with me, and went up the road to both BP and Shell.Both had 91 regular at $1.53 per litre.
I put 3lts in one at Shell,and 3lts in the other at BP-drove home and poured them both into my 10lt gardening spray pot.
Well what do you know! BP was 3lts spot on- Shell was 2.90lts- 100ml less.
Isn't that a lot over such a small fill?
Or is it not that simple-

Anyway, I'm filling up at BP now...what a pity I don't have a Gull station around the corner!

DBourne · 12-08-2007, 11:53 AM

hang on... you're saying you always put in $40 not 40 litres...

well wouldnt the amount of petrol you get in the car depend on fuel prices?
eg. petrol @ $1 p/l you would get 40 litres for your 40 bucks.. and less if petrol was more expensive?

maybe i missed the point but thats how i saw it, so no real mystery..

blacklabel · 12-08-2007, 12:14 PM

Quote:

Originally Posted by SgtBourne

hang on... you're saying you always put in $40 not 40 litres...

well wouldnt the amount of petrol you get in the car depend on fuel prices?
eg. petrol @ $1 p/l you would get 40 litres for your 40 bucks.. and less if petrol was more expensive?

maybe i missed the point but thats how i saw it, so no real mystery..

The price was the same-at all 3, that's why I can't see the variation.
Otherwise,yes,you would be correct.
But when you get "x" ammount more at the same price- thats what got me thinking,hence my question.

BPXR6T · 12-08-2007, 12:23 PM

I usually fill up at the local caltex when I hit 1/4 tank. I typically get charged for 10 litres over the tanks capacity. That's a lot considering I already had 1/4 tank in there.

Falc'man · 12-08-2007, 12:30 PM

Yeh if the pumps aren't working correctly - sometimes you can even hear them not working properly, they make a flapping noise indicating less fuel being pumped through. As soon as you hear this stop filling and move on to the next servo. (you'd be stuffed if you heard it at the next servo as well lol)

**Full Noise** · 12-08-2007, 03:15 PM

Quote:

Originally Posted by Falc'man

Yeh if the pumps aren't working correctly - sometimes you can even hear them not working properly, they make a flapping noise indicating less fuel being pumped through. As soon as you hear this stop filling and move on to the next servo. (you'd be stuffed if you heard it at the next servo as well lol)

This isn’t really the case. I understand what you’re saying about the noise when they sound like they’re pumping air, but I can assure you than when the numbers are moving on the display, it’s pumping fuel. Most new servos use semi-submerginal pumps that are located on top of the actual tank, so they run silently.

Lightning Strike GT · 12-08-2007, 03:40 PM

There was an independant just up the road from me and i filled 2 containers to the full mark on each 1 5 litre and 1 10 litre = 15 litres
The pump put out over 17 litres on the dial and took a few photos with the phone camera, the 2 containers, the readout and the serial number on the side of the bowser
Made a few inquiries to the ACCC sent them the photos times and date and pump number and servo location

bobkatz · 12-08-2007, 08:11 PM

Quote:

Originally Posted by BF XR8

took a few photos with the phone camera,location

You shouldnt use your phone near the pumps, maybe you should be the one who gets a fine

mik · 12-08-2007, 10:16 PM

Quote:

Originally Posted by bobkatz

You shouldnt use your phone near the pumps, maybe you should be the one who gets a fine

they had that on myth busters with the mobile phone and petrol pump, their responce was not not ignition wont happen

Lightning Strike GT · 14-08-2007, 11:24 AM

Quote:

Originally Posted by bobkatz

You shouldnt use your phone near the pumps, maybe you should be the one who gets a fine

Who told you that crock of crap it is an urban myth

:

smally289 · 12-08-2007, 12:34 PM

Do you guys really think that when a fuel gauge reads 1/4 that it means a 1/4 of the total tank volume? Fords fuel gages have always been inaccurate, get used to it!

Im pretty sure that servo's have their bowsers checked regularly for accuracy by law.

apolloxbgt · 12-08-2007, 12:44 PM

Quote:

Originally Posted by smally351

Im pretty sure that servo's have their bowsers checked regularly for accuracy by law.

I thought they only have them randomly checked,and the rest of the time it's up to them.

svo347 · 12-08-2007, 12:45 PM

Quote:

Originally Posted by smally351

Do you guys really think that when a fuel gauge reads 1/4 that it means a 1/4 of the total tank volume? Fords fuel gages have always been inaccurate, get used to it!

Im pretty sure that servo's have their bowsers checked regularly for accuracy by law.

I used to work at a servo during my apprenticeship, the have to be calibrated every 6 mths by law

**Sorted** · 12-08-2007, 01:01 PM

Quote:

Originally Posted by svo347

I used to work at a servo during my apprenticeship, the have to be calibrated every 6 mths by law

So that just means they can be accurate for 1 month and be out for the other 5 months

Its not like they are gong to call you back there and tell you that they have to give you a credit as they overcharged.........

xy500 · 14-08-2007, 12:34 PM

Quote:

Originally Posted by DRHEMI

So that just means they can be accurate for 1 month and be out for the other 5 months

Its not like they are gong to call you back there and tell you that they have to give you a credit as they overcharged.........

Everybody seems to have a case of the distrusting bug.
service station pumps are calibrated very carefully and the calibrations are locked in place- these are checked AT LEAST every 6 months often more than that, and in my experience they are never out more than 0.001 of a litre at the worst. these things don't just 'go out' and i'm sick of hearing people say that "my car only takes 60 litres and it just took 62 litres" that means your car just did take 62 litres, not that the pump is wrong, all factory capacity measurements aren't for if the tank is full up the the spout, they are for the tank only! so try find a witch somewhere else because beleive it or not this is an issue service stations and the government regulate very closely.
col

Jesk · 12-08-2007, 03:14 PM

Quote:

Originally Posted by svo347

I used to work at a servo during my apprenticeship, the have to be calibrated every 6 mths by law

true but also you forget to say everytime a technician touches a pump even if only to replace a globe in it the pump must be re-calibrated usually with all the stuff happening I see most pumps getting calibrated once every couple of months and thats only on my shifts! also note on the basic 10L calibration the lowest I've seen come up is the pump saying 10.03L and the highest is saying 9.94L so the biggest discrepancy is to the customers advantage. The reason they get tested so often is that some idiots have no idea what the capacity of their tank is! eg, only this morning I had some bloke in a VN complaining that he got 54L into his '50L' tank in his commo, I tried to tell him that that age commo had around 65L tank (checked myself later actual capacity is 63L) but he stuck by his guns so hes got the stuff to ring up so again our pumps will be calibrated so as you see it happens regularly.

BTW i work for Coles Express and have done so since high school

AlbertM · 12-08-2007, 01:56 PM

At local caltex one pump spat out 20% more than you actually paid. It became my favourite pump and waited for even others were free.

This lasted for 3 months until others caught on and the station attendand wondered why people were queing for that one pump. They shut down the pump for a couple of days and they fixed it.

The Monty · 12-08-2007, 03:10 PM

In the AU it also depends how youve been driving the car. Maybe you have been driving more sedatley, which means the fuel needle will be further up the fuel gauge.

groops · 12-08-2007, 03:39 PM

Can't say I've ever personally had this issue...I ususally get the whole...'Hold on, Ford claim my tank is 68L and I can't ever get more than 56L in when I fill'. Even when DTE is under 10km to go and red light has been on for 2 days... I don't have an issue with it.

Mike

Unco · 12-08-2007, 06:23 PM

Quote:

Originally Posted by groops

Can't say I've ever personally had this issue...I ususally get the whole...'Hold on, Ford claim my tank is 68L and I can't ever get more than 56L in when I fill'. Even when DTE is under 10km to go and red light has been on for 2 days... I don't have an issue with it.

Mike

same here. mine's supposed to be a 79L tank (???) but i've never been able to put any more than 66L... and that was after running out of fuel!!!

prydey · 12-08-2007, 06:40 PM

there are also HUGE fines to the servo's if they are found to be doing the dodgy.

i use the same servo about 95% of the time but on occasion, i use one a bit further up the road of the same company. when i do i notice i have to hold the nozzle so that the fuel only trickles out otherwise it keeps clicking off. not sure if this is a delivery pressure or storage temp issue but it doesn't do it when i fill up at the earlier station.

other than that i don't really worry to much cos when i'm paying $90+ every tank, whats another couple of dollars.

mrw82 · 12-08-2007, 05:48 PM

i work for gilbarco who perform maintenance and calibration on fuel pumps for most of the big name servos, i have to say most customer complaints are bull.
firstly calibration intervals are left to the fuel companys. all fuel companys get it done regularly most are 6months. they are not required to be calibrated every time we work on them, only if we adjust or remove/replace a component that affects calibration.
calibration tolerances are TIGHT. it is a maximum of 0.05% which over a 60 litre tank of fuel is a maximum of 200ml. not even a cup full!
thats legal limits, fuel companys have their own tighter tolerances we have to stick to.
if the meter is faulty it would be rare (more chance of winning lotto) that it would ever be enough for the customer to really notice. also if its faulty it will be in the customers favour! they're designed to wear out that way.
you cannot fill up a jerry can to the line to check for accuracy, those containers are rough, they have room for fuel vapour expansion and are not accurate, dont do it you are guaranteed dodgy results!
as for pumping air, it wont happen. the pump units have a built in air separator unit, if there is too much air the pump will stop dispensing. if there is no fuel passing through the meter, the meter wont turn, which means the display wont click over and you wont be paying for any fuel. it is illegal to SELL air and the pumps are designed so that it cant happen.
one of the major complaints servos get is a ****er in a commodore saying ' i got a 50 litre tank and i just put 55 litres in it'. car tanks are rough sizes, and have extra capacity for vapour expansion. if you keep 'clicking' the nozzle after your tanks full you fill the expansion area, which can be dangerous, so dont do it.

ok im done, fire at will.

Jesk · 12-08-2007, 07:56 PM

Quote:

Originally Posted by mrw82

i work for gilbarco who perform maintenance and calibration on fuel pumps for most of the big name servos, i have to say most customer complaints are bull.
firstly calibration intervals are left to the fuel companys. all fuel companys get it done regularly most are 6months. they are not required to be calibrated every time we work on them, only if we adjust or remove/replace a component that affects calibration.
calibration tolerances are TIGHT. it is a maximum of 0.05% which over a 60 litre tank of fuel is a maximum of 200ml. not even a cup full!
thats legal limits, fuel companys have their own tighter tolerances we have to stick to.
if the meter is faulty it would be rare (more chance of winning lotto) that it would ever be enough for the customer to really notice. also if its faulty it will be in the customers favour! they're designed to wear out that way.
you cannot fill up a jerry can to the line to check for accuracy, those containers are rough, they have room for fuel vapour expansion and are not accurate, dont do it you are guaranteed dodgy results!
as for pumping air, it wont happen. the pump units have a built in air separator unit, if there is too much air the pump will stop dispensing. if there is no fuel passing through the meter, the meter wont turn, which means the display wont click over and you wont be paying for any fuel. it is illegal to SELL air and the pumps are designed so that it cant happen.
one of the major complaints servos get is a ****er in a commodore saying ' i got a 50 litre tank and i just put 55 litres in it'. car tanks are rough sizes, and have extra capacity for vapour expansion. if you keep 'clicking' the nozzle after your tanks full you fill the expansion area, which can be dangerous, so dont do it.

ok im done, fire at will.

fair enough mate I was just going from what I've seen my end but you would have the official line on that enquiry

mrw82 · 13-08-2007, 04:41 PM

as i said earlier

Quote:

Originally Posted by mrw82

one of the major complaints servos get is a ****er in a commodore saying ' i got a 50 litre tank and i just put 55 litres in it'. car tanks are rough sizes, and have extra capacity for vapour expansion. if you keep 'clicking' the nozzle after your tanks full you fill the expansion area, which can be dangerous, so dont do it.

looks like its not just commodore drivers tho.

:

irsa76 · 12-08-2007, 06:54 PM

mrw82, quick question for you. For a long time I've heard the story that if you fill up on a cold morning you get slightly more fuel then if you fill up in the middle of a hot day. While I know petrol does expand when hot, I have doubts that the difference is noticable. Can you shed any light on this?

**Full Noise** · 12-08-2007, 07:56 PM

Quote:

Originally Posted by irsa76

mrw82, quick question for you. For a long time I've heard the story that if you fill up on a cold morning you get slightly more fuel then if you fill up in the middle of a hot day. While I know petrol does expand when hot, I have doubts that the difference is noticable. Can you shed any light on this?

Ill have a go at this.

I can assure you that this is absolute bull. Fuel volume does expand with heat, however, over a 60 litre fill it would be impossible to know of any difference, also because the fuel is stored underground, there is very little heat transfer. On a 40 degree day, the fuel underground will generally be the same temperature as fuel in a 10 degree day. When the servo purchases fuel from a supplier, they pay for the fuel at whatever the fuel volume is at 15 degrees Celsius. This is known as temperature correction.

Although many people would choose not to believe, the chances of a customer getting the short end of the stick at a servo is extremely rare.

P.S. I don’t work for Gilbarco or Metric, although 11 years driving petrol tankers teaches you a few things about fuel.

jarridtheruler · 12-08-2007, 07:39 PM

Well my ba futura i6 took 75L once, and it already had fuel in the tank. The cashier at the counter didn't care at all, she reckoned it wasn't her problem.
In the end i didn't bother arguing too much over it, and i never went there again. i doubt i could get them to pay up anyway

irsa76 · 12-08-2007, 08:02 PM

Thanks Full Noise, I thought that was the case even though I know some people refuse to buy fuel during the day.

smally289 · 12-08-2007, 09:44 PM

Yep, all those dangerous sparks that fly out of mobile phones are dangerous around fuel!! What a load of rubbish.
The static electricity you produce getting out of the car is 10 times more likely to ignite fuel vapours than a mobile. As is the door switch for the interior light.

mrw82 · 12-08-2007, 10:28 PM

the rumor about getting more fuel in the morning has something to do with the density of fuel at different temps, as the pumps have inbuilt vapour separators you would be getting nothing but pure petrol from the nozzle. making no difference whenever you fill up.
the thing with the nozzle clicking off all the time is to do with the flowrate of the fuel and also the venturi in the nozzle. it may be a dodgy nozzle at the second place (let them know about it and if its a common thing, not just one customer, they'll get it looked at) or it could be that the flowrate of the pump is too high.

Moble phones: i agree that the dangers are a load of bull, but its the law that a phone cannot be used on the forecourt of a service station. the main danger (as smally351 said) is static charge, but its the distractions while talking on the phone which increase the likely hood of a static discharge which makes phones dangerous.

keep the question coming i'll put to rest as many myths and rumors as i can.