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firefox
03-03-2007, 04:17 PM
Does petrol in car tank evaporate on hot days? What percentage of petrol goes to waste by evaporation.?.does anyone know anything on this and maybe share with us the findings. Thanks.

hhtee
03-03-2007, 09:54 PM
I would think one could do their own experiment. weight your car by putting weighing machines under the 4 wheels. method 1
the weighing machine may be expensive since you r weighing about 500kg per wheel depending on your car. leave your car for a few weeks n see if your car's weight reduces.

method 2
alternatively, get a few steel containers. measure 4 levels at the corners of a tight container. then measure 4 levels of a partially / fully exposed container. keep measuring every day for a week or two.

now you have data of evaporation of petrol in
A) air tight container
b) partially / exposed contaIner

finally please publish these data at usj.com.my :d

USJ27Resident
04-03-2007, 01:12 AM
Found the same questions on another forum (http://www2.abc.net.au/science/k2/stn/february2000/posts/topic38989.shtm) ...

... logically, petrol tanks are tightly sealed with your petrol cap... right? So unless you forget to put it back or you have a "rosak" spring on your petrol cap... it should not be leaking/evaporating much petrol....

... then again, i could be wrong..

cheers

CCY
04-03-2007, 12:22 PM
Surefire way of checking it out....
Fill your tank to the brim cap it and leave your car alone for a month. After that , open the cap and check the level...
Announce the results ya...:rolleyes:

Alternatively this is another foolproof faster test for petrol vapourisation.
Light a match at the petrol tank cap and if there is a kaboom sound then not so good.:eek: Don't do it when you still have another day to live....

TiNKeRFY
04-03-2007, 12:42 PM
Surefire way of checking it out....
Fill your tank to the brim cap it and leave your car alone for a month. After that , open the cap and check the level...
Announce the results ya...:rolleyes:

erm.. if the car's petrol tank is full for a whole month, wouldn't that mean the car's stationary for a full month? by the time you find the result, the car's battery would be dead... :p



Alternatively this is another foolproof faster test for petrol vapourisation.
Light a match at the petrol tank cap and if there is a kaboom sound then not so good.:eek: Don't do it when you still have another day to live....
erm.. whoever doing this, pls annouce which area you're staying, I'll be a good samaritan and be prepared to call in the fire department... when i'm miles away...

the petrol car tank is completely sealed, so there shouldn't be any evaporation to occur... unless the seals at the cap is worn off, or the fuel hose is leaky... or someone told you they pump in full tank for you, which in fact is only "almost full" and claim full payment from you.. :D

jericho
04-03-2007, 10:53 PM
Does petrol in car tank evaporate on hot days? What percentage of petrol goes to waste by evaporation.?.does anyone know anything on this and maybe share with us the findings. Thanks.


evaporation does occurs in the petrol tank. evaporation rate grows higher when the amount of petrol decreases in the tank due to greater surface area exposed. having said that, it is not good either to fill the petrol to the max because extra room in the petrol tank is needed to allow the petrol to expand.

the amount of petrol lost due to evaporation is extremely small and insignificant if you are concern about cost saving.

firefox
05-03-2007, 07:33 AM
Thanks Jerico for your reply and tips.

hhtee
05-03-2007, 09:31 AM
I still prefer to experiment what rate of evaporation exists in a closed container and a not closed container.

But har har. Loooks like it's easier said than done. I had been thinking about this for some time but yet no action i.e. I didn't do that experiment.


Besides, I don't have a lab to have a constant temperature like say 25C, 26C, 27C, 28C, 29C 30C, 31C ,etc

patrick
05-03-2007, 09:42 AM
evaporation does occurs in the petrol tank. evaporation rate grows higher when the amount of petrol decreases in the tank due to greater surface area exposed. having said that, it is not good either to fill the petrol to the max because extra room in the petrol tank is needed to allow the petrol to expand.

the amount of petrol lost due to evaporation is extremely small and insignificant if you are concern about cost saving.

Like Jericho said, the % is sooo small, it just aint worth the while. The other prudent reason for not filling your tank to the max is some cap may not be leak proof and there is the possibility of spillage. And worse, damaging your body paintwork.

chin_wan
05-03-2007, 02:59 PM
Alternatively this is another foolproof faster test for petrol vapourisation.
Light a match at the petrol tank cap and if there is a kaboom sound then not so good.:eek: Don't do it when you still have another day to live....

This is like the suicide bomber school where the teacher would say..."Watch carefully, as I can only show you once how to conduct a suicide mission!"

Life Ranger
05-03-2007, 03:28 PM
Someone ever told me before that if the gasoline is "old" - ie. left in the tank for long like more than a week, it will lose much of its octane by evaporation which results in loss of power. Therefore always fill up for a few days' usage and refill with "fresh" one by then.

I always fill up RM40 each time and refill after 300 km in 3-4 days. The car's performance and the quality of gasoline can easily be monitored this way via the mileage.

Choon1980
05-03-2007, 03:30 PM
Another way is to submit this question to Mythbusters. Why bother risking your own life with flammable material when Adam and Jamie get PAID to do so? :rolleyes: :p ;)

hhtee
05-03-2007, 03:37 PM
Another way is to submit this question to Mythbusters. Why bother risking your own life with flammable material when Adam and Jamie get PAID to do so? :rolleyes: :p ;)
WHY must WE DO THAT?

We can have our own Made in Malaysia's Malaysian "Mat MythBusters".

Ok, who is gonna sponsor this show :D