Volume correction at the gas pumps

[Patman]

On the gas pumps it mentions that the volume is corrected to 15C, and I was wondering how much this actually affects the amount of gas we get? For instance, if you are pumping gas on a hot summer day compared to the coldest winter morning, how much of an actual volume difference is there?

The main reason I'm asking is because I'm trying to fine tune my scangauge and I'm wondering if the manual calculation I'm getting from the number given to me on the gas pump is skewed a lot by extreme cold weather? So in order to get the most accurate calibration should I be doing my scangauge fine tuning when the ambient temperature is closer to 15C?

 

[Shannow]

15C is typically what the ground temperature is at the level of the tanks...YMMV depending on where you live, but that's a point that ground sink heat pumps and a whole lot of other stuff are set at.

So your pumps should be compensating for the tanker full of fuel that has just driven 4 hours in the sun, and dumped a hot load into the tank.

Oz won't go to temperature compensation, so I really should fill up on the way to work, when chances are that it's a stable, ground temperature.

As to your fine tuning, energy consumption should be in thermal units, which is more accurate than mass units, which is (as per the discussion) WAY more accurate than volume units...so yes, try to be at 15C if you can.

 

[kschachn]

I agree with Shannow that all things being equal we should be paying for energy content, much like we do for natural gas. But that's not practical at the pump.

I once linked a story that showed that even at the same gas station the energy content of the gasoline varied by up to 4%. For real world fuel economy testing a standardized test fuel is used to eliminate this variable.

So do we have temperature compensation here in the US?

 

[Patman]

Originally Posted By: kschachn


So do we have temperature compensation here in the US?


I believe it happens everywhere in the US, I do recall seeing it listed on the pumps at stations I have filled up at in Florida and in NY state.

 

[thunderfog]

Originally Posted By: Shannow
and dumped a hot load into the tank.


I *just* finished doing that.


Sorry in advance for my immaturity.

Back to topic, if I can remember the volume equations for liquids, the differences should not be that significant.

 

[Cujet]

Here in S. Florida, I've been to a gas station that actually had "hot" fuel. You could feel it in the handle. They had above ground tanks painted white.

I don't go there anymore. However, after a 2 week cold snap, maybe that's the place to go...

 

[HTSS_TR]

Costco stations are very busy all day, most of the time more than 2-3 vehicles or more are waiting on each line, also all tanks are under ground so that the fuel coming out of the pump is always cool, probably around 50-60F.