Email re: filling cars with petrol - is this genuine?

madaminx

TIPS ON FILLING YOUR CAR(S)

• Only buy or fill up your car or bakkie in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the fuel, when it gets warmer petrol expands, so buying in the afternoon or in the evening....your litre is not exactly a litre.
  
  In the petroleum business, the specific gravity and the temperature of the petrol, diesel and jet fuel, ethanol and other petroleum products plays an important role. A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.

• One of the most important tips is to fill up when your tank is HALF FULL.. The reason for this is, the more fuel you have in your tank the less air occupying its empty space. petrol evaporates faster than you can imagine. Petroleum storage tanks have an internal floating roof. This roof serves as zero clearance between the petrol and the atmosphere,
  so it minimizes the evaporation. Unlike service stations, at fuel pipelines, every truck that is loaded is temperature compensated so that every litre is actually the exact amount.

• If there is a fuel truck pumping into the storage tanks when you stop to buy, DO NOT fill up--most likely the petrol/diesel is being stirred up as the fuel is being delivered, and you might pick up some of the dirt that normally settles at the bottom.

• When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3) stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapours that are created while you are pumping. All hoses at the pump have a vapour return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapour. Those vapours are being sucked up and back into the underground storage tank so you're getting less worth for your money.

DO SHARE THESE TIPS WITH OTHERS!

TadleyBaggie

This one has been doing the rounds for a long time http://www.snopes.com/inboxer/household/gastips.asp

Lum

In addition to that US-centric Snopes article, In the UK the pumps compensate for temperature so it makes no difference anyway.

Alfrescodave

Here we go again !!!!
Should also be time for the "lets boycott the major oil producers which will force them to lower their fuel prices" email as these 2 favourites usually resurface together.

Weird_Nev

I'm mainly annoyed at the .9p scam! they're ripping off consumers to the tune of literally lots a year because of rounding errors!

moonrakerz

Weird_Nev wrote: »

I'm mainly annoyed at the .9p scam! they're ripping off consumers to the tune of literally lots a year because of rounding errors!

........and THIS one again !!!!!

moonrakerz

To return to the OP...........

On 16-17 August 1989 a QANTAS 747-400 flew non-stop from London to Sydney, the first time this had ever been done by a commercial airliner. Most of the seats/galley equipment/etc had been removed to lighten the aircraft.
The aircraft was filled to overflowing with special fuel which had been cooled - 183.5 tonnes. The aircraft was towed to the runway before the engines were started.
On arrival in Sydney there were 5.6 tonnes of fuel (45 mins flying time) remaining.

Must be something in it ..........:D

scheming_gypsy

Weird_Nev wrote: »

I'm mainly annoyed at the .9p scam! they're ripping off consumers to the tune of literally lots a year because of rounding errors!

that much eh!!

Lum

moonrakerz wrote: »

Must be something in it ..........:D

Yes there is, but British petrol pumps compensate for it when calculating how many litres have pumped.

The Weights&Measures people can be very strict about things like this.

This email is American in origin and, if the Snopes article is correct, then their pumps do not adjust for this, however the tip is still invalid because of the temperature issues described in that article (tank temperature having little relationship to ambient temperature)

So in the case of the plane described above, it was just a trick to cram more fuel into the standard sized tank.

colino

Few British Pumps accurately change delivery taking into account temperature as per standard temperature accounting (STA), largely because the difference in volume through temp change, is so small. When trading standards do a garage for short measures, they really must have been taking the mick because the proper calibration of test amounts actually takes into account the volume change in the metal standard measure tank that they use and has a calculation for that change. If memory serves me right that difference is a tiny 1mL difference for every 1C. Living in the temperate climes of the UK the volume change, because of the relatively small temperature differences, the difference in fuel delivery would not only be negligible, but probably not accurately measureable!
Just like when people believe that they can detect the performance gains in their car when it is cold and damp (denser air) this is all a bit cod science.

Lum

I thought the thing about colder air improving performance was only for forced induction cars with big front mount intercoolers, and was more to do with improved cooling of the hot air from the turbo rather than the density of the air entering through the air filter.