filling fuel better cold in the or.

[EK1]

hey,

just wondering whats the best time to fill petrol in a car.. is it better to fill it when its cold in the morning or hot in the afternoon. thanks

[DJKOR]

FFS man. This is just as stupid of a question as your last fuel related one. There is a thread questions like this:

The STUPID thread

Common sense and a Google search would tell you that generally, liquids become more dense when cold. That's about all I need to say with respect to that, providing you use your head.

As for any advantages, you aren't going to make any measurable difference to how much fuel you get.

[Kenshin X]

ouch

[Andrew357]

FFS man. This is just as stupid of a question as your last fuel related one. There is a thread questions like this:

The STUPID thread

Common sense and a Google search would tell you that generally, liquids become more dense when cold. That's about all I need to say with respect to that, providing you use your head.

As for any advantages, you aren't going to make any measurable difference to how much fuel you get.

Hey, hey man...

Over 100 years you might.

[Hiro]

As a rough guide, the density of petrol increases about 0.5% for every 5 degree drop (assuming you don't go to extremes). Thus, if the morning is say 10 degrees cooler than the afternoon, then you are getting an absolutely massive 1% saving in the amount of petrol when you fill up (assuming the bowsers are calibrated on flow-rate, not mass transfer). 1% of a 50L tank is half a litre, so you're saving 60c or so on a full tank.

Then again, petrol is stored in big underground tanks which are very good insulators. Ground temperature stays pretty much constant all year around, day or night (which is how ground-source heat pumps act as air-con in the summer (when the ground is cooler than the air-temp) and heaters in the winter (ground is warmer than air-temp). Thus, the temperature of the petrol is highly unlikely to change until it is sitting in your petrol tank and slowly absorbing heat, well after it has passed through the bowser.

So either way, fail. Don't believe everything you read on the internet, kids.