Does Gas Temp make a difference in mpg?

[tripleM]

I couldn't find a discussion on this (though I am sure there is 1 floating around): What is the consensus on fuel temp in regards to fuel economy.

It would seem fueling during the day would get me more volume but that is different from what these articles say:

Doesn't matter

Hot gas cost money

 

[XS650]

Gas station tanks are usually underground so fuel temperature doesn't vary with time of day.

 

[tom slick]

The funny thing about the "hot gas" concept is they choose to cite the physics that gas expands as it warms but they choose to ignore the physics that the earth where the tank is located a constant temperature and is insulated due to the double or triple liner. The first couple of gallons could be warmer from sitting in the pump and hose but the expansion of a gallon or two is not very much, even with a 20-30* raise in temperature.

also in the wintertime you are getting "cold gas" so in theory you are getting "more gas" then what you pay for.

 

[mikered30]

I think you are talking about very small difference, you probably could not even measure it.

 

[Max_Wander]

Originally Posted By: tom slick
The funny thing about the "hot gas" concept is they choose to cite the physics that gas expands as it warms but they choose to ignore the physics...



and the fact that MOST gas pumps are poorly calibrated on the optimistic side. Case in point, take a 2 gallon gas can and fill it up to its marked capacity, and then look at the register tally....

 

[tom slick]

you think a mass produced roto-molded plastic can is more accurate then a pump that is cal'd at least once a year?

I was at the station when the county weights and measures tech was certifying the pumps. they maintain less then 1.5% volume error as measured out of the nozzle.

 

[firemachine69]

Originally Posted By: Max_Wander
Originally Posted By: tom slick
The funny thing about the "hot gas" concept is they choose to cite the physics that gas expands as it warms but they choose to ignore the physics...



and the fact that MOST gas pumps are poorly calibrated on the optimistic side. Case in point, take a 2 gallon gas can and fill it up to its marked capacity, and then look at the register tally....



If you have an equal amount as fuel pushing on the sidewalls of the canister as someone crunching on your gut, you'd be puking.

 

[Lazy JW]

There is a thread over at SpeedTalk on a similar subject.

http://speedtalk.com/forum/viewtopic.php?p=116821#116821