Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - is it true that a full tank gives better mileage?

dcb · 09-11-2008, 10:33 AM

Here are some more "facts" to help figure it out:
New Hampshire's Gasoline Vapor Recovery Program - Protecting the Air We Breathe

"eleven pounds of VOCs may be released for every 1,000 gallons of gasoline during fuel transfers. "

Assuming 6.5 lbs/gallon for gasoline, the volume of the vapor represents about 11/6500 of an equivalent volume of liquid gasoline. Or another way to look at it is the vapor density is 0.17% of the liquid density.

It shouldn't matter vapor wise if you put in 5 gallons in two fillups, or 10 gallons in one fillup, you are putting 0.17% VOC back into the pump (or into the air) in the form of vapor. The obvious difference between the two is the amount of weight you carry around.

09-11-2008, 10:33 AM	#15 (permalink)
dcb needs more cowbell Join Date: Feb 2008 Location: ÿ Posts: 5,038 pimp mobile - '81 suzuki gs 250 t 90 day: 96.29 mpg (US) schnitzel - '01 Volkswagen Golf TDI 90 day: 53.56 mpg (US) Thanks: 158 Thanked 269 Times in 212 Posts	Here are some more "facts" to help figure it out: New Hampshire's Gasoline Vapor Recovery Program - Protecting the Air We Breathe "eleven pounds of VOCs may be released for every 1,000 gallons of gasoline during fuel transfers. " Assuming 6.5 lbs/gallon for gasoline, the volume of the vapor represents about 11/6500 of an equivalent volume of liquid gasoline. Or another way to look at it is the vapor density is 0.17% of the liquid density. It shouldn't matter vapor wise if you put in 5 gallons in two fillups, or 10 gallons in one fillup, you are putting 0.17% VOC back into the pump (or into the air) in the form of vapor. The obvious difference between the two is the amount of weight you carry around. __________________ WINDMILLS DO NOT WORK THAT WAY!!! Last edited by dcb; 09-11-2008 at 11:25 AM.. Reason: (bad math, had to fix)