Hi,

I have a '12 Sport Auto with around 6K on it. I decided to see how far I could run the tank down to ( I know; not a good idea but I wanted to see how accurate the gas gauge was). When my low fuel light came on, I drove another 12 hwy miles, then filled it up. The manual says that I should have 1.6 gallons left when the light goes on. It took 10.7 gallons to fill it up. I did not over fill it; nothing overflowed.

My question is this: If I had around a gallon left in the tank, that would mean the fuel capacity of the fit was around 11.7 gallons. Maybe this is because there is a long pipe from the tank under the seat to the filler cap that adds another gallon, or what? Does Honda somehow understate the size of the fuel tank?

Thanks

 

Your not supposed to fill up the pipe. I stop once it clicks. Ive seen bad things happen to people who over fill.

 

As said, overfilling is when you fill beyond the first click.

I always fill at a quarter tank, and put in 7-8 gallons.

 

Every car I have owned I have filled it till the gas can be seen. Been driving for the last almost 24 years and not once have I ever had an issue. What bad things have you seen?

 

Ive seen bad things happen to people who over fill.[/quote]
Describe "bad things", please. I used to routinely fill my '07 w/ as much as it would take, and never had anything bad to happen.

 

Yes, but you guys tend to leave out the fact that lot of people tend to be missing common sense.

As for me I wouldn't do anything like that just as a precautionary thing. It also makes me nervous when people fill their cars up with the car running, talking on their phones, or aren't paying attention in general.

Then again, I'm sort of a paranoid person mainly cause I use to work in customer service and realized how stupid some people really are.

I'm not trying to say its a bad thing per say to fill it all the way up. Just that it leaves more room for error

 

haha, OK I will agree with you to an extent as I always say I have uncommon sense because what I deem common these days is rampant ignorance.

 

Sometimes it causes problems with evaporative control systems for some cars. My Altima acted retarded when I overfilled it.

 

FYI, The way a gas pump nozzle works is it shuts off when fuel reaches and covers a port at the end of the nozzle. So when it clicks off, fuel is already most of the way up the filler pipe.
When you are topping off, you are only going to be filling that last bit of pipe equal to the length of the fuel nozzle; but at the risk of messing up evap control systems.

As far as underestimating/overestimating, I think they probably just measure the tank. There are issues when you get really low in terms of if you're on a downhill your car works but you go on an upslope and the fuelpump can't get to that last gallon that's actually in your tank.

Given the lowest common denominator in intelligence in the American market, they will probably just quote the fuel tank volume rather than saying "this is how much fuel the car will really hold, but actual amount of fuel that can be accessed depends on the slope in which you are operating the vehicle". Perhaps in a German manual they'll have the calculations for that more complex explanation (see also example that world manuals has more details on motor oil, not just "use 5/0-20" always!)

 

nitpick: evap systems were only mandated in 1996. Depending on your car buying history, only some of those cars would have an issue.

The issue is that you're mostly filling the evap canister. If it overfills, it can stop working, set a check engine light, and require replacement. Some cars are more prone to the problem than others. I also wouldn't be surprised if it also does the same thing to the gas station's vapor recovery equipment.

 

Well I have only owned cars from Honda and since '96, 4 that fall into that time frame of manufacture, but only 1 of those 4 were a US spec model (nanny glorified systems there). Never had any issues and never a CEL about the evap system. Until something drastic happens I will continue filling as I always do, though I seriously doubt I will see anything negative since it has been this long already and I drive quite a bit using lots of fuel.

 

I will have been filling to the top of the fill tube for 3 months shy of 6 years.... I've done likewise on three injected motorcycles, a van, pickup, one NA Volvo and one with intercooled turbo... I've never had any kind of problem from doing it yet... I've sure been called a lot of names by people that are convinced that my car will one day need to be taken to a dealership to be repaired... It hasn't been wrenched on by a dealership or any other shop so far for anything.

 

"nitpick: evap systems were only mandated in 1996. Depending on your car buying history, only some of those cars would have an issue."

Actually evaporative systems were mandated in the USA in 1971. See this link.

Milestones | Mobile Source Emissions | US EPA

Quote from link.

"1971: New cars must meet evaporative emission standards for the first time; charcoal canisters to trap gasoline vapors are developed."

I have owned 3 or 4 71 cars and all had evap systems.

Clifton

 

Crap, my bad, its 1996 when all that got tied together into OBDII.

 

This now falls into the "I'm smarter than the designers of the car" type discussion.

Manual says don't top off. So do the instructions at every fuel station.

Sure, most of the time maybe it won't f-up your evap system, and maybe if some fuel gets in there, it'll dry out most of the time and not trigger a code. But that one time it does f-up YOUR car and you got to pay to replace your charcoal canister to pass smogcheck, you'll be regretting your decision.

Plus, do a cost-benefit analysis. What exactly are you gaining other than winning an internet debate that this is something you can do.

As I mentioned before, if you investigate how fuel filler nozzles work, you're not really gaining that much more volume to store gas. And not like Range is really that big of an issue where we're having a longest range competition. Also, a portion of that extra gas that you're pumping hits an overflow or gets "consumed" via the evap system in a non-efficient way as compared to the gas in the tank that gets converted into miles.

End of the day, it's your car do whatever you want with it.

 

I couldn't have said it any better myself.

 

Thanks for the explanations guys. I will fill it past a click or two, but that's it.

Part of what spurred this on was that with my other vehicles (later year Tundra and Audi), when the pump clicked off the first time, the gas was fairly close to the filler neck. With the Fit, it seemed easy to get another gallon in without seeing the gas near the gas camp. And although we can do cost benefit analyses until the cows come home, an extra 10% of fuel capacity does/would help.

Interesting discussion.......

Wafit

 

The assumption is that you think the extra fuel went in the fuel tank and not just to the evap system or other overflow system that just dumps it out.

Again, the pumps click off when fuel hits the nozzle. So really think where that extra gallon is going. I personally don't think all the fuel you pump is actually going to be used effectively; so you might as well just pump most of that extra gallon onto the ground.

 

While this might be possible, empirically I consistently see another 30 plus miles out of a tankful when I top it off. Since my mileage averages around 32 mpg, based on my observations, most of the fuel in that last gallon is being used. If any, a negligible amount is being lost.

Of course, you still run the risk of damaging your emissions system.