(Actually everything expands with temperature.) Haha, somebody was trying to calculate mpg based on fuel mass, speed, and rpm (all apparently available from a Ford 350 ECU) and I was thinking that gallons is volume, and mass is well... mass. So if gas expands with heat then you'd need a temperature factor to convert from mass to volume. I drove a semi for many years and I know for a fact that if you top off a 75 gallon tank with diesel and let it sit with the motor off on a hot day that you'll end up with a good sized puddle on the ground. Googling found the actual formula to derive the coefficient of expansion... but I couldn't read it. Wikipedia (not guaranteed to be right) had some actual numbers. A couple of other articles were about how people think they're getting ripped off at the pumps on hot days. First the expansion part. From the wikipedia numbers it looks like it's linear (at least in the range of 60*F to 90*F and gas will expand about 2% in volume with that 30* rise. It also appears that gas tanks in cars are designed so that they're not completely full when the gas backs up the filler tube to shut off the pump nozzle. That air/vapors is much more compressable -- which I guess could be important now that cars don't have vented caps any more. It also seems that gas is priced, per gallon, at a temperature of 60*F. So people are figuring they get ripped off on hot days cause they get less gas (mass or molecules) per gallon out of the pump. I don't buy this so much. All the gas stations I go to have their tanks underground. Once you go about a foot underground (or below the frost line) the temperature is pretty constant all year around and probably pretty close to 60*. I just KNEW that everyone who didn't already know this would be fascinated, so I though I'd share :grin:
Dave, you'll probably get as much interest in this as when I start rally racing threads!!! LOL However, since I made this comment, there will more than likely be multiple pages of responses.
I didn't exactly expect a thundering response. That's why I put it in the lounge. Good to see you back Bud.
Blow me Cam....if you were taking a pot shot at me. Thanks brother....if you were taking a pot shot at Dave! Thanks "Quick"....glad to see we are still on a screen name basis!!! LOL
Haha. You do know that I'm probably going to call you Bud when we meet in person too. I can't think of anyone that fits that nick more than you. Your folks just misnamed you. See if you find this thread of more interest. DadsSrt8 has some observations/questions on page 2. http://www.srtconnection.com/forums/showthread.php?t=13786
Neither, it was just your regular everyday average pot shot........ya know, in the general sense. :flowers:
since this is in the lounge ... Yea of course gas expands, especially in my gut after eating Taco Bell!! (sorry Dave, couldn't resist)
