Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: duggs on 12 June 2008, 23:19:09
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Some of you guys may have seen this email BUT..its a VERY interesting read and it seems logical. With our 2.5 and 3.0 V6's it could save a packet.
"I don't know what you guys are paying for petrol.... but here in Durban we are also paying higher, up to R7.35 per litre. But 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 Marian Hill Pipeline where I work in Durban, 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, LRP and Unleaded. We have 34-storage tanks here with a total capacity of 16,800,000 litres.
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.
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.
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, 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 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 on the bottom.
Hope this will help you get the most value for your money".
DO SHARE THESE TIPS WITH OTHERS! "
Now ! Interestingly I filled up the car this morning, from 2/3 full expecting it to come to about £18.00...it was full at £16.00. using the pump trigger on a quarter to half "throttle" . More interestingly the auto cut off didn't kick in...perhaps because there wasn't all the vapour abd guggling involved with a "full throttle" fill up.
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Thanks for those great tips Duggs! :y :y
It is amazing what you know when 'in the trade' ;D ;)
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Ah, right thats a old message, based in the US from circa 1999 to 2007
http://www.snopes.com/inboxer/household/gastips.asp
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Cheers for that I will give it ago :y
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Blimey...NOT only is it old but almost the same...word for word with a few strategic alterations...
Still..its worth knowing...which I didn't...until now.
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Either way, very interesting information.
I noticed filling up a few times the auto cut off kept kicking in and now, thinking back, it was allways on warm, hot days. :y :y
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Now then, i wondered while reading the part about filling when half full that any gain would be lost by driving around with the waight of a permanently full tank. :-? but 2 quid ceaper for 1/3 of a tank?????
i like the sound of filling early a.m. my shift starts 6 am! :y
Thankyou kindly. ;)
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Sorry .. I disagree with most of this ...
Only buy or fill up your car or bakkie in the early morning when the ground temperature is still cold.
Fuel storage tanks are well below the ground .. often 10-15 feet to the TOP of the tank, let alone the bottom... at these depths the temperature is virtually constant throughout the year .. let alone changing overnight !!!
low speed, thereby minimizing the vapours that are created
Vapour is caused by the latent heat of evaporation, not by fast filling/stirring etc etc ... .. in order to evaporate fuel absorbs heat from the atmosphere ... so it could be argued the faster you fill then seal your tank with the filler cap the less you lose .. but it is probably less than 1/10 a teaspoon full difference !!
the more fuel you have in your tank the less air occupying its empty space. petrol evaporates faster than you can imagine.
Modern fuel tanks are vapour sealed to prevent polution .. thats why the fuel injector system has a return to the tank, and you get a "shush" noise when you open the tank .. so no fuel vapour can escape from a sealed system ...
you might pick up some of the dirt that normally settles on the bottom.
The tank pickup is some way off the bottom just for this reason, and the pumps have filters fitted as well ...
More interestingly the auto cut off didn't kick in...perhaps because there wasn't all the vapour abd guggling involved with a "full throttle" fill up.
The autocut of is activated by pressure .. vapour cannot produce pressure in an "open" system .. it is liquid that operates it ... if you pump slowly you get less "splash back" so fewer "cutoffs"
from 2/3 full expecting it to come to about £18.00...it was full at £16.00.
To fill a tank takes a specific volume of liquid .. the difference between £16 and £18 is over a litre .. do you really think a few little tricks like this can save you THAT much fuel ?? .... IMHO you simply overestimated how much you needed ..
Just my opinion BTW ... :)
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Sorry .. I disagree with most of this ...
Only buy or fill up your car or bakkie in the early morning when the ground temperature is still cold.
Fuel storage tanks are well below the ground .. often 10-15 feet to the TOP of the tank, let alone the bottom... at these depths the temperature is virtually constant throughout the year .. let alone changing overnight !!!
low speed, thereby minimizing the vapours that are created
Vapour is caused by the latent heat of evaporation, not by fast filling/stirring etc etc ... .. in order to evaporate fuel absorbs heat from the atmosphere ... so it could be argued the faster you fill then seal your tank with the filler cap the less you lose .. but it is probably less than 1/10 a teaspoon full difference !!
the more fuel you have in your tank the less air occupying its empty space. petrol evaporates faster than you can imagine.
Modern fuel tanks are vapour sealed to prevent polution .. thats why the fule injector system has a return to the tank, and you get a "shush" noise when you open the tank .. so no fuel vapour can escape from a sealed system ...
you might pick up some of the dirt that normally settles on the bottom.
The tank pickup is some way off the bottom just for this reason, and the pumps have filters fitted as well ...
More interestingly the auto cut off didn't kick in...perhaps because there wasn't all the vapour abd guggling involved with a "full throttle" fill up.
The autocut of is activated by pressure .. vapour cannot produce pressure in an "open" system .. it is liquid that operates it ... if you pump slowly you get less "splash back" so fewer "cutoffs"
from 2/3 full expecting it to come to about £18.00...it was full at £16.00.
To fill a tank takes a specific volume of liquid .. the difference between £16 and £18 is over a litre .. do you really think a few little tricks like this can save you THAT much fuel ?? .... IMHO you simply overestimated how much you needed ..
Just my opinion BTW ... :)
Agreed TBH
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In that case then it would be interetsting to see the Top Gear test rerun with the V8 Audi to Scotland and back from London on a hot sunny day starting with an empty tank at 2pm and see what the difference is.
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In that case then it would be interetsting to see the Top Gear test rerun with the V8 Audi to Scotland and back from London on a hot sunny day starting with an empty tank at 2pm and see what the difference is.
Dont forget the air density on a hot day is less and will effect the running of the motor, much like driving at high alitudes.
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In that case then it would be interetsting to see the Top Gear test rerun with the V8 Audi to Scotland and back from London on a hot sunny day starting with an empty tank at 2pm and see what the difference is.
Dont forget the air density on a hot day is less and will effect the running of the motor, much like driving at high alitudes.
Air density will probably affect performance, and thus fuel usage, far more than the items above ... as will hot days when folks either run aircon harder, or open windows/sunroofs and increase the drag co-efficient substantially !!
Best (most efficient) operation will always be mid-winter .. :)
(actually a cold, dry day, in the bottom of a deep valley is best .. :) as you get the highest air pressure then .. :) )
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have heard similar things in the past, interesting stuff, but lets get the price of fuel down , we just keep getting ripped off :-X
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However ! I've yet to come across a motorist who doesn't think that the first half of a full tank goes down slower than the bottom half.
I've driven a variety of vehicles over these past 27 years or so and in every case, the first half lasts longer in terms of milege than the last half. Why is that prey tell ?
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Thames valley ok? commute Reading to Slough. ;D
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In that case then it would be interetsting to see the Top Gear test rerun with the V8 Audi to Scotland and back from London on a hot sunny day starting with an empty tank at 2pm and see what the difference is.
Dont forget the air density on a hot day is less and will effect the running of the motor, much like driving at high alitudes.
All above my head Jon, but I find some of the theory very interesting allthough not allways the case in reality.
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Hey everyone has an opinion, thats what makes us all unique :)
I am prepared to try anything that might help the squeeze on me poor old pocket at the mo!! :y
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Its dead simple mate .... to burn petrol efficiently you need 14.7 times as much air as there is petrol, by mass, (known as the stoichiometric ratio)... when the air pressure is low the engine takes in less air, so the ECU gives less fuel, so you have less power ... most folks don't know this and compensate by flooring it a bit more ... so using more fuel as well as making the ratio "wrong" by overfuelling to get more "power" ... inefficient operation.
On a cold dry day when the air pressure is high its little like having a tiny turbo on your car ... more air = more fuel = more power, so you can back the throttle off a tad ... more efficient operation.
HTH :)
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my old ZX9(edited;sorry thats a motor bike, just in case you wondering) used to run noticably smoother and crisper in cold air temps.esp after a warm day. throttle response much improved. went like slippy snot until carb icing stopped play. they never did sort that prob. :-?
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Its dead simple mate .... to burn petrol efficiently you need 14.7 times as much air as there is petrol, by mass, (known as the stoichiometric ratio)... when the air pressure is low the engine takes in less air, so the ECU gives less fuel, so you have less power ... most folks don't know this and compensate by flooring it a bit more ... so using more fuel as well as making the ratio "wrong" by overfuelling to get more "power" ... inefficient operation.
On a cold dry day when the air pressure is high its little like having a tiny turbo on your car ... more air = more fuel = more power, so you can back the throttle off a tad ... more efficient operation.
HTH :)
That confirms a few things for me.
I allways felt my my car went a lot better at 6 am on the wy to work rather than the trip home at 4 pm. I put it down to tighter tolerances on the engine being cold and "Tight" rather than being hot and "losr"
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However ! I've yet to come across a motorist who doesn't think that the first half of a full tank goes down slower than the bottom half.
I've driven a variety of vehicles over these past 27 years or so and in every case, the first half lasts longer in terms of milege than the last half. Why is that prey tell ?
Could be a number of explanations such as the guage is not linear.
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However ! I've yet to come across a motorist who doesn't think that the first half of a full tank goes down slower than the bottom half.
I've driven a variety of vehicles over these past 27 years or so and in every case, the first half lasts longer in terms of milege than the last half. Why is that prey tell ?
I must say mate I experience quite the oppoisite. have always wondered why though.
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My diesel astra goes noticably better when colder. Especially in the evenings.
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However ! I've yet to come across a motorist who doesn't think that the first half of a full tank goes down slower than the bottom half.
I've driven a variety of vehicles over these past 27 years or so and in every case, the first half lasts longer in terms of milege than the last half. Why is that prey tell ?
quite simple really, the bottom half of the tank is smaller!!! top half has almost sqaure edges bottom half has sloping edges to push the fuel into the centre for the pick up pipe, thats a simple explanation but it gives you the gist of i :yt!!
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Its dead simple mate .... to burn petrol efficiently you need 14.7 times as much air as there is petrol, by mass, (known as the stoichiometric ratio)... when the air pressure is low the engine takes in less air, so the ECU gives less fuel, so you have less power ... most folks don't know this and compensate by flooring it a bit more ... so using more fuel as well as making the ratio "wrong" by overfuelling to get more "power" ... inefficient operation.
On a cold dry day when the air pressure is high its little like having a tiny turbo on your car ... more air = more fuel = more power, so you can back the throttle off a tad ... more efficient operation.
HTH :)
You might actually find the opposite is true. You'll have more power with colder air but, when cruising on part load, thinner, hotter air will require less throttling of the engine, which actually improves its' efficiency.
Any difference is probably lost in the noise though.
Kevin
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Very interesting read bud nice one will think on in future.. :y
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Omega toy...How can that be possible..Despite the shape of the tank...the fuel gauge shows how much was and how much is left.
The top 35 litres takes longer to go than the bottom 35 litres...?
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how much does the filler neck hold??? got more than 70 litres in myn acouple of times, i am sure.
brim it rather than stop at the first click off. first half is then more than 70 ltrs??? :-?
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Omega toy...How can that be possible..Despite the shape of the tank...the fuel gauge shows how much was and how much is left.
The top 35 litres takes longer to go than the bottom 35 litres...?
The shaped tank explaination is correct, although I would have said the shaping was more to do with making the tank fit the available space!
As for the guage... Remember it isn't calibrated, it's just a guide! It's fed from a potentiometer which just gives a linear resistance output as the float arm drops. Fuel guages are notoriously inaccurate at the best of times!
I hope this helps you with the mystery!
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Good point.....
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Ironically, a warm yet misty morning is probably the theroetical most efficient time to drive as the water vapour in the air makes for a more complete (read efficient) burn, so more "bang for your buck" as they say. The warmer air doesn't affect modern injection systems - but it will decrease the air density, hence the drag on the vehicle. The fuel/air ratio will be unchanged is its 14.7:1 by WEIGHT - not volume.