Fillup Question

I attempt to "top off" each and every time. That is not always possible -- if someone is in line, or if the pump is super sensitive. Did this for 350,455 miles with my Scion. Did throw a evap code, but was of little concern to me as I live in an area where auto inspections do not include emissions.

 

Finally... this is the first time I have heard a verification that it actually does something. Did the car drive any differently?

 

If it DOES something, it is 'just' going to be that it pollutes more heavily. It is not a driveability issue. Have you known anyone who tested to see if their gas tank emissions had risen?

 

Considering I live in Atlanta and have to get my emissions done every year... yeah. I know people that get their emissions checks done. Nothing significant on my Saturn, or my wifes mazda, or my fathers GMC 1500, or my mothers Kia. The changes in emissions generally had more to do with needing a tune-up than the evap... but then, seeing as we have never had to repair an evap in all 4 vehicles... who knows.

 

Georgia's Clean Air Force: Emission Testing

None of these tests will detect evaporative emissions, that I am aware of. (aside from a bad gas cap)

Vehicles prior to 1996 use a tailpipe probe called a ASM2 test, it also is not going to be testing evaporative emissions, just tailpipe emissions.

Vehicle emissions control - Wikipedia, the free encyclopedia

I am still doubtful anyone is routinely testing evaporative emissions or reporting the results.
Evaporative Emissions Testing

I read all this, but it does not address our issue, they omitted cars with saturated charcoal canisters. http://www.epa.gov/otaq/emission-factors-research/420r10025.pdf

 

No issues with the vehicle performance or mpg.

 

I could show you the exact numbers by ppm for the last 10 years... but you would probably still not believe me. When I go get an emissions test, they give the report. They probe the new cars too.

But those are probably different emissions than what you are looking for... if there was a "real" problem, it is supposed to throw a code... correct? If there is a check engine light you will not pass the emissions testing.

 

I believe you completely, but I still think those are tail pipe emissions, not evaporative emissions from the gas tank.

I would doubt that it would throw a code, I do not think there IS a gas tank ECU. Overfilling the gas tank is not going to be an engine problem.

 

Not a Prius c, but there was this:
Multiple Evap Codes | PriusChat

and this:
confirmed overfill damage | PriusChat

 

Actual evidence... finally. Granted it is a gen 2 with a bladder... those things were notoriously bad... but still evidence.

 

That is the whole point of an evap code... po 440/1/2 They get thrown when there is evap damage.

 

Cool, I enjoy being wrong as it means I learn new stuff!

 

Speaking of learning new stuff, read this!

Overbeck Auto » CAN’T FILL THE GAS TANK?…MAYBE IT’S A BAD BATTERY!

 

Good to know...

 

If you're arguing between getting another decimal point out of your MPG stats or causing yourself car problems when you could have avoided them, I say go for it. Be the example, good or bad. Pays your money and takes your chances. Be hard headed.

Tell us how it goes.

From the owner's manual of the C:

When refueling
Observe the following precautions to prevent fuel overflowing from the fuel tank:
-Securely insert the fuel nozzle into the fuel filler neck
-Stop filling the tank after the fuel nozzle automatically clicks off
-Do not top off the fuel tank

Refueling

Do not spill fuel during refueling.
Doing so may damage the vehicle, such as causing the emission control
system to operate abnormally or damaging fuel system components or the
vehicle's painted surface.

 

So this will affect you accuracy of

Who is this directed at?

 

Whomever feels it may be is welcomed to believe it is. I have no axe to grind, and regularly ignore safety guards, conventional wisdom, and the politically correct.

I'm just saying that topping off a tank in a habitual fashion on a different vehicle that may have issues with that action may not be in a person's best interest.

 

Most cars have a warning about his. Dating back to before OBD2. Most cars don't have an issue with this. My luck though, I'd be that 5%

 

You guys are funny I have always filled my Prius to the top of the filler neck. After the pump clicks off,
I pull the nozzle out and slowly fill it to the top of the neck. I don't keep the nozzle in the tank and keep popping the handle. I've done this on my 08 Prius Liftback and have been doing the same with my 2013 Prius C. As long as you're not forcing the fuel into the tank by popping it with the nozzle inserted into the filler neck, you can't force the fuel into the Evap Canister.

I am able to add 2 gallons to the tank after it kicks off. It's the only way you can get a 100% accurate calculations

 

Since you are willing to be experiment A, can you let us know if you ever get a PO440/1/2 code come on? I'm still curious about this.