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Tips on buying petrol


Adrian@TORQEN

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Got this by email, how real is it?

 

I don't know what you guys are paying for petrol.... I am paying up to £1.35 to £1.50 per litre. My line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every Litre:

 

Here at the Shell Pipeline where I work , we deliver about 4 million litres in a 24-hour period .. 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 of 16,800,000 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 stations have their storage tanks buried below ground. The colder the ground the more dense the petrol, 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.

 

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. You should be pumping on low mode, 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.

 

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 in your tank the less air occupying its empty space. petrol evaporates faster than you can imagine. petrol 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, here where I work, every truck that we load is temperature compensated so that every litre is actually the exact amount.

 

Another reminder, if there is a petrol truck pumping into the storage tanks when you stop to buy Petrol, DO NOT fill up; most likely the petrol is being stirred up as the Petrol is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

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Well the bit about petrol expanding and contracting is a bit of an overreaction. it's true that it does it, and quite a lot under large temperature changes, but thefuel is stored in HUGE underground reservoirs that whilst not temperature compensated are still very resistant to temperature change due to being a large body of liquid insulated by lots of ground. The kind of temperature differences that get thrown around in these arguments (the kind that would make a real difference to how much fuel you were getting) just don't happen, so although the theory is sound, it just doesn't translate into the real world.

 

Just to back myself up here, this is coming from an aviation background where you want to be VERY sure how much fuel you actually have in the aircraft. If pilots and ground crews consider the difference to be negligible and safe to ignore, then i think differences in cars with much smaller tanks are going to be close to zero.

 

DB

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It's b*llocks.

 

Someone did the maths on it last time it came round and it worked out that you could save a whopping 33p a year, or something equally daft like that. Any nonsense about the vapours is peanuts compared to the weight saving from driving around with 1/4 of a tank rather than a full one.

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I can do a little PVT analysis but I wouldn't bother for the 2-3 degC difference you'd likely see.

 

The evaporation argument I'm unsure of fully but if you actually use a vehicle it won't make much difference.

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Yeah its going to save you jack all money - ok if you are pumping 16m barrels a day or whatever 0.1% is important, for your 30 litres at a fill up that 0.1% is intangible. You can save more money by just not booting it away from the lights...

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Love the bit where is says keep the trigger on LOW mode.

 

It already takes me forever at the pump when I fill up from empty, so if I had it on LOW mode, id be there for like half an hour or something.

 

As it is I get strange looks as Nissan Micra owners come in, fill up and drive away and im not even 1/3rd of the way through filling the 350`s tank up.

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