Fuel fill-up mystery - Page 4 - Unofficial Honda FIT Forums

2nd Generation (GE 08-13) 2nd Generation specific talk and questions here.

Fuel fill-up mystery

  #61  
Old 04-26-2011, 12:50 PM
Member
5 Year Member
Join Date: Apr 2011
Location: Rochester, NY
Posts: 44
More on mileage

Originally Posted by CrystalFiveMT View Post
Stopping for gas lowers MPG? Well, don't you have to stop for gas in every car? You can fill up your tank, drive for 1/4 tank and fill up, it's still going to return the same fuel efficiency as if you drive the whole tank.
************************************************** *
New member, this thread is interesting, even though it occasionally goes way off topic. Back to the quote above from Xtal5:

It's true, your fuel mileage has very little to do with how frequently you stop for gas. I say very little, because it WOULD affect mileage if you took it to ridiculous limits - ie. if you filled up, drove 2 miles and returned for more gas every 2 miles of driving. All those stops and starts would adversely affect mileage. But lets be reasonable and figure you aren't buying gas until the tank is half full or less. That would have negligible impact on your fuel economy. It would increase the amount of time you spend filling up is about all. More fillups equals more time.

What does affect mileage is driving habits (most important of all), automatic vs. manual tranny, tire pressure, type of tire, speed, ambient temperature, weather (heavy snow vs. sunny and dry), altitude above sea level, engine tune, air filter new or clogged, oil (dino vs. synthetic), road conditions such as flat, hilly or curvy and whether windows are open or closed, and accessories like A/C, fan, etc. on or off.

Lastly, I noticed a bit of misinformation in this thread. Yes, when you refuel your car, some gas vapors escape into the atmosphere. Refueling more often will NOT cause more vapors to escape. Some states have laws requiring a special vapor recovery system with an accordian pleated rubber device which sucks the vapors escaping from your tank back to the gas station's tank.

Many states do NOT have such laws and the gas pump nozzle is plain old steel tubing. In those states, the frequency of filling up has almost nothing to do with how many vapors escape. What does matter is how many gallons you put in the tank. If you put ten gallons in, you displace twice as much vapor than if you put 5 gallons in, it's simple math. Nothing at all to do with how often you buy gas.

When the tanker truck fills the underground tanks, they use a vapor recovery system, so as the truck empties, it's filled with the vapors escaping from the underground tanks. Those vapors are hauled back to the fuel depot, where they in turn go into the depot tank as the tanker truck is refilled. It's a theoretically closed system, better for the environment. At least this covers about 2/3 of the vapors released in the whole process, except for the vapors from your cars tank in the states without recovery laws. I realize I only brought us back to the fuel depot, not to the refinery just to keep things simple
 
  #62  
Old 04-26-2011, 01:47 PM
Member
5 Year Member
Join Date: Jul 2009
Location: SF Bay Area
Posts: 670
Originally Posted by KwazyKwaig View Post
************************************************** *
New member, this thread is interesting, even though it occasionally goes way off topic. Back to the quote above from Xtal5:

It's true, your fuel mileage has very little to do with how frequently you stop for gas. I say very little, because it WOULD affect mileage if you took it to ridiculous limits - ie. if you filled up, drove 2 miles and returned for more gas every 2 miles of driving. All those stops and starts would adversely affect mileage. But lets be reasonable and figure you aren't buying gas until the tank is half full or less. That would have negligible impact on your fuel economy. It would increase the amount of time you spend filling up is about all. More fillups equals more time.

What does affect mileage is driving habits (most important of all), automatic vs. manual tranny, tire pressure, type of tire, speed, ambient temperature, weather (heavy snow vs. sunny and dry), altitude above sea level, engine tune, air filter new or clogged, oil (dino vs. synthetic), road conditions such as flat, hilly or curvy and whether windows are open or closed, and accessories like A/C, fan, etc. on or off.

Lastly, I noticed a bit of misinformation in this thread. Yes, when you refuel your car, some gas vapors escape into the atmosphere. Refueling more often will NOT cause more vapors to escape. Some states have laws requiring a special vapor recovery system with an accordian pleated rubber device which sucks the vapors escaping from your tank back to the gas station's tank.

Many states do NOT have such laws and the gas pump nozzle is plain old steel tubing. In those states, the frequency of filling up has almost nothing to do with how many vapors escape. What does matter is how many gallons you put in the tank. If you put ten gallons in, you displace twice as much vapor than if you put 5 gallons in, it's simple math. Nothing at all to do with how often you buy gas.

When the tanker truck fills the underground tanks, they use a vapor recovery system, so as the truck empties, it's filled with the vapors escaping from the underground tanks. Those vapors are hauled back to the fuel depot, where they in turn go into the depot tank as the tanker truck is refilled. It's a theoretically closed system, better for the environment. At least this covers about 2/3 of the vapors released in the whole process, except for the vapors from your cars tank in the states without recovery laws. I realize I only brought us back to the fuel depot, not to the refinery just to keep things simple
In theory true, but if you've ever observed a full tanker fillup procedure, when they disconnect the lines they have about a gallon or so of fuel in the lines/connectors that they just drain out into a plain 5gallon plastic bucket which they leave to evaporate away. There goes the vapor savings

So it's not really about saving the fuel or environment, although that is a secondary benefit they promote.

So rather than saving fuel, the vapor recovery primarily seems to be a safety feature to exchange volumes of fluids, so you don't have displaced volatile vapor being outgassed in a concentrated stream, and avoid your customers smelling like gasoline.
 

Last edited by raytseng; 04-26-2011 at 02:02 PM.
  #63  
Old 04-26-2011, 03:07 PM
Texas Coyote's Avatar
Member
5 Year Member
iTrader: (3)
Join Date: Oct 2007
Location: Anderson County Texas
Posts: 7,388
I have 118 miles on this tank which I filled to the top of the tube a couple of weeks ago like I always do... It needle on the odometer is still to the right of the full mark.
 
  #64  
Old 04-26-2011, 10:27 PM
Member
5 Year Member
Join Date: Apr 2011
Location: Rochester, NY
Posts: 44
Originally Posted by Boba Fitt View Post
Today I filled up with 9.69 gallons, about 2 miles after the light came on. This would mean only a 1 gallon capacity after the light- not what Honda says.
Assuming the light runs off of the gas gauge, and knowing that gas gauges are notoriously innacurate in general, I wouldn't think of their numbers as a guarantee.
I bet you could have gotten more than 9.69 gal in if you'd pumped it very slowly. I filled up my '07 Fit today, 62 miles after the light came on. I put 13.006 gallons in! There was room for more, but I got tired of running it in so slowly. Still couldn't see the gas level in the filler pipe as I have on a couple recent fillups.

Anyone looking to stop for gas less often might be interested in this info. This tells me I'm easily good to drive 50 miles after the light comes on. 1.7 gallons times 37 mpg = 62.9 miles which provides a safety cushion.
 
  #65  
Old 04-26-2011, 10:40 PM
Member
5 Year Member
Join Date: Apr 2011
Location: Rochester, NY
Posts: 44
Originally Posted by Texas Coyote View Post
I have 118 miles on this tank which I filled to the top of the tube a couple of weeks ago like I always do... It needle on the odometer is still to the right of the full mark.
Hey T.C.,
Did you pay extra to have a needle on your odometer? I only have a needle on my fuel gauge, speedo, tach, etc. My odometer is plain Jane digital. I would love to see an odometer needle, sounds really cool

Just havin' fun...

All kidding aside, I've noticed when I fill my Fit to the brim, the fuel gauge stays a couple needle widths above full mark for quite a few miles. Now that you comment on it, I'll have to notice how many miles to get down to Full mark. I've owned many cars which take a lot longer to go from Full to Half, than they take to go from Half to Empty. I'm guessing car makers do that to reduce the chance you'll run out of gas. Once you notice the gauge dropping rapidly you're more likely to stop for gas.
 
  #66  
Old 05-02-2015, 11:45 PM
New Member
Join Date: May 2015
Location: New Zealand
Posts: 2
Originally Posted by KwazyKwaig View Post
Hey T.C.,
Did you pay extra to have a needle on your odometer? I only have a needle on my fuel gauge, speedo, tach, etc. My odometer is plain Jane digital. I would love to see an odometer needle, sounds really cool

Just havin' fun...

All kidding aside, I've noticed when I fill my Fit to the brim, the fuel gauge stays a couple needle widths above full mark for quite a few miles. Now that you comment on it, I'll have to notice how many miles to get down to Full mark. I've owned many cars which take a lot longer to go from Full to Half, than they take to go from Half to Empty. I'm guessing car makers do that to reduce the chance you'll run out of gas. Once you notice the gauge dropping rapidly you're more likely to stop for gas.
I think you will find that the reason fuel gauges go down faster on the lower half of the scale is because they use a linear float gauge but the tanks are not linear. They are bigger at the top. Also they set them up so that empty is not the bottom of the tank usually.
I had a Mazda van that ran out when the fuel guage got to the end of the empty block. Happened the day I bought it. Car dealer gave it to me empty and having always found some reserve on other vehicles I figured I could fill it up at a convenient station on the way home only I didn't quite make it.
 

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.