Don't Top Off Your Tank!

[johnf514]

Posted from: http://www.epa.gov/donttopoff/
Don't Top Off Your Gas Tank!
HELP PROTECT THE ENVIRONMENT!
SAVE MONEY!


* Do you top off your gas tank and overfill it?

* When the gas pump nozzle clicks off automatically, do you add a little more gas to round off your dollar sale?

* Topping off your gas tank is bad for the environment and your wallet.

Here's why:

Topping off the gas tank can result in your paying for gasoline that is fed back into the station's tanks because your gas tank is full. The gas nozzle automatically clicks off when your gas tank is full. In areas of ozone nonattainment, gas station pumps are equipped with vapor recovery systems that feed back gas vapors into their tanks to prevent vapors from escaping into the air and contributing to air pollution. Any additional gas you try to pump into your tank may be drawn into the vapor line and fed back into the station’s storage tanks.


Gasoline vapors are harmful to breathe. Gasoline vapors contribute to bad ozone days and are a source of toxic air pollutants such as benzene. Evaporation from the spillage of gas from overfilling can occur, contributing to the air pollution problem. Remember you pay for the gas that evaporates or is spilled on the ground.

You need extra room in your gas tank to allow the gasoline to expand. If you top off your tank, the extra gas may evaporate into your vehicle’s vapor collection system. That system may become fouled and will not work properly causing your vehicle to run poorly and have high gas emissions.


Topping off your gas tank may foul the station's vapor recovery system. Adding more gas after the nozzle has automatically shut off can cause the station's vapor recovery system to operate improperly. This contributes to the air pollution problem and may cause the gas pump to fail to work for the next person.

[philmcneal]

only if you know you'll burn that gas immediatley is when you should top off, when wayne knew he had to travel more than a 1000 miles to his destination.

For my car parking at night makes the gauge goes below half, but in the morning when it has sitted in the sun all nice and toasty the fuel gauge spikes over half again! Wee free gas.

[detectorguy]

I Let the pump shut off and then round to the nearest dime. Sure don't get much more

[Sulfuric]

Originally Posted by detectorguy

I Let the pump shut off and then round to the nearest dime. Sure don't get much more

Same here.

[Mendel Leisk]

I completely agree with the OP. Trying to squeeze in a bit more gas in is a fools game. When the pump clicks off, dub it done.

Another fools game: running your tank dry.

[xcel]

Hi Mendel:

___I will disagree. Not topping off means yet another wasted trip into a gas station to refuel. Those extra 1 to 4 gallons over 4 tanks can allow one less stop every 4 or 5 tanks.

2011 Ford Super Duty


2010 Kawasaki KLX250SF


2009 BMW 335d


2010 Prius-III


2008 HCH-II


2008 Yamaha XT250


2009 Corolla XRS


2007 Civic iCDTi


2001 Honda Insight

___As just a few.

___Good Luck

___Wayne

[vtec-e]

I top off as best i can too but i drive a diesel so there is less of a worry about vapours. It foams like hell though and it can take some time to fill it right up. I could have 6 or 7 litres to go when it would click out. That's pretty excessive imo.
Still though, i wouldn't mind knowing how exactly the vapour recovery system works. I was thinking this recently as the pump nozzle was enveloped in foam while i topped off the tank. I pulled the nozzle back out a little so it wouldn't rob my foam!
"Thats my foam! I paid for it!!" lol

ollie

[Ophbalance]

Hmm... how is it a fools game? Letting the pump determine my fill means 380 miles until I see the flashing pip (fill up in 30 miles, or else, more or less). When I take the time to fill to what the tank can actually handle, my range is 540 miles until I see the flashing pip. I dunno about you, but 380 miles won't see me through a week, but 540 will.

[brick]

As much as I would like to have a 600 mile range, I'm content to let the pump click off and deal with 350-500mi depending on how stretchy the bladder feels. There have been multiple reported $1000 Prius tank replacements due to fouled evap systems from overfilling. It might be a small risk but it still isn't worth it to me.

Then there's what I saw last weekend on the Mass Pike. I pulled into west-bound Lee rest stop behind a Nissan Sentra (no surprise...he had passed me at 15+ over the PSL not too far back) and we started filling at about the same time. I got out, pumped my 7 gallons, got back in, wrote down my numbers, and saw that I was boxed in and had to wait for the guy. And wait. And wait. And wait.

The reason for the wait was that he kept on topping off the tank click after click after click after click. Eventually I noticed the vapors start to pour out of the filler neck past the nozzle's emissions control. Maybe 15 seconds after that this jackass actually had gasoline pouring down his paint. I was going to politely (probably not) point this out but I guess he decided that was enough and put the nozzle back.

So guess what I got? A cabin full of fumes! Captain Click took off ahead of me with a hydrocarbon trail that just wouldn't quit...he must have had liquid gas pouring out the breather line or something.

So you guys do what you want. Personally I'd like to make use of my car's PZEV feature. (Obviously this isn't really a problem for diesel people...one considerable benefit of low-volatility fuel.)

[Mendel Leisk]

Originally Posted by Ophbalance

Hmm... how is it a fools game? Letting the pump determine my fill means 380 miles until I see the flashing pip (fill up in 30 miles, or else, more or less). When I take the time to fill to what the tank can actually handle, my range is 540 miles until I see the flashing pip. I dunno about you, but 380 miles won't see me through a week, but 540 will.

Just doing a little rough math: say your tank capacity to the pump shut-off point is 40 liters (sorry, Canadian, I'll convert at the end). Just going by your range difference, 540/380, You appear to have nearly 17 liters (nearly 4.5 US gallons) worth of capacity in your tank filler pipe.

Wayne,

I figure our tank filler pipe might have 1 liter (optimistically). Our tank's 45 liters. If I run it till the warning comes on, it takes about 37 liters. So with that liter in the neck I'm neglecting to fill, I'm filling 1/37 more frequently than I should be. Now, our fillups almost invariably coincide with my wife dropping off some mail, I roll another 100 yards to the station, on weeks we need to fillup.

All-in-all, this is not having a big impact, particularly balanced against possible spillage.