True or false

[Russ]

recently told that "premium" fuels are at times topped up with ethonol by sellers, i understood this grade was always pure...............tell me i've heard wrong.

 

 

[Russ]

TIPS ON PUMPING PETROL

 

 

 

I don't know what you guys are paying for petrol.... buthere in Melbourne we are paying up to $1.30 to $1.50 per litre.

 

My line of work is in petroleum for about 31 years now, so here are some tricksto get more of your money's worth for every litre:

 

 

Here at the Shell Pipeline where I work in Melbourne, we deliver about 4 million litres in a 24-hour period thru the pipeline..

 

One day is diesel the next day is jet fuel, and petrol, regular and premium grades.

 

We have 34-storage tanks here with a total capacity of16,800,000 Litres.

 

 

Only buy or fill up your car or truck in the early morning when the ground temperature is still cold.

 

Remember that all service stationshave their storage tanks buried below ground.

 

The colder the ground themore dense the petrol, when it gets warmer petrol expands, so

 

buying in the afternoon or in the evening....your litre is not exactlya litre.

 

In the petroleum business, the specific gravity and thetemperature of the petrol, diesel and jet fuel, ethanol and otherpetroleum 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 thepumps.

 

 

When you're filling up do not squeeze the trigger of the nozzleto a fast mode.

 

If you look you will see that the trigger has three (3)stages: low, middle, and high.

 

You should be pumping on low mode, thereby minimizing the vapors that are created while you are pumping.

 

 

All hoses at the pump have a vapor return. If you are pumping on thefast rate, some of the liquid that goes to your tank becomes vapor.

 

 

Those vapors are being sucked up and back into the underground storagetank so you're getting less worth for your money.

 

 

 

 

One of the most important tips is to fill up when your petrol tank is HALF FULL.

 

The reason for this is the more petrol you have inyour tank the less air occupying its empty space.

 

Petrol evaporatesfaster than you can imagine.

 

Petrol storage tanks have an internalfloating roof.

 

This roof serves as zero clearance between the petrol andthe atmosphere, so it minimizes the evaporation.

 

Unlike servicestations, here where I work, every truck that we load is temperaturecompensated so that every litre is actually the exact amount.

 

 

Another reminder, if there is a petrol truck pumping intothe storage tanks when you stop to buy petrol, DO NOT fill up;

 

mostlikely the petrol is being stirred up as the petrol is beingdelivered, and you might pick up some of the dirt that normally settles on the bottom.

 

 

 

 

[.Evan.]

Interesting read, Russ! Thanks for sharing.

 

 

[FlyingVizsla]

I got that as an email about 5 years ago supposedly from a guy who works at an oil refinery in California. The savings in temperature contraction would be infinitesimal against the idea of buying at the coldest hour - and besides that, it is sitting fairly well insulated in massive tanks. Oh well, nice thought.

 

Sue

 

 

[Exadios]

I got that as an email about 5 years ago supposedly from a guy who works at an oil refinery in California. The savings in temperature contraction would be infinitesimal against the idea of buying at the coldest hour - and besides that, it is sitting fairly well insulated in massive tanks. Oh well, nice thought.Sue

I would not expect the tank temperature to change very much over a day, but over a year there is probably a difference of 3 degrees C. So I think the trick is to wait until it has been snowing for a month and fill up then, but not before!

 

 

[.Evan.]

Glad I'm using autogas.

 

 

[winsor68]

One local servo here sells Premium Ethanol... works out a wee bit cheaper than standard unleaded... I wouldn't put it in an aeroplane.

 

 

[horsefeathers]

Having actually worked at both Brisbane oil refineries (first BP, and then Ampol, as it was then), pipelines from refineries to terminals (where the petrol/diesel tankers load) indeed can contain different products at different times.

 

HOWEVER, when a product change is made (say from diesel to ULP), the interface (a known quantity of the mixed product) is sent to a "slops" tank, which is obviously a mix of all sorts of different products. This slop tank is then shipped back to the refinery, and is then re-refined (it just becomes another feedstock, actually). After the interface is removed, the clean product is then sent to its particular product tank.

 

Temp differences on the product end make for minimal volumetric differences, just BTW. Not worth changing the time of day you buy. The servo tanks are in the ground - they are effectively isolated completely from daily (as in diurnal) temp changes.

 

As for Avgas, typically, there is a dedicated pipeline to the airport, that is not used for any other product.

 

Dont know about ethanol mixing, but I do know that the fuel is tested by the refinery by its own NATA registered lab before it hits the pipelines. What then may happen at the terminal (where the tankers load) is up to the terminal operators - they may mix additives at that point. Does anyone work at a terminal who can comment on additive blending?

 

 

[Spriteah]

Lol love the thread. The petrol you get out of a tank has been batched. If you used a company such as shell (I work for them) or mobil or other safe companies then you get petrol that will meet a company spec. Mostly above Australian specs. If you fuel up anywhere you should get specs that meet aust standards but the are not high.

 

Ethanol is not good for lots of fuel and tank components so be careful with that one. In will dissolve plastics, ect and clog your carbie.