Overfill?

You overfill your oil when you put more then ~3.5 quarts of oil into it.

You know when its over filled when you see the oil above the "max" line on your oil dipstick.

 

i filled my tank last time and at 9.12 gallons it came spurteling out at me. i took a gas bath as did my prius. last time i try to fill it up to full!:flame:

 

See link below....

If you overfill your tank (e.g. try to top off after the pump shuts down) you run the risk of having fuel spill over into the charcoal canister that helps reduce emissions from the fuel tank (I believe that is what it does).

Long and short of it....

If you top off the fuel tank, you might incur about a thousand dollars or more worth of repairs needed to pull out the fuel tank/bladder to replace the canister and replace the whole ensemble. Don't top off.

There are numerous threads on this, perhaps in the fuel economy or tech discusson sections. One had pics of a dissection of a fuel tank.

EDIT

http://priuschat.com/forums/care-ma...56-fuel-tank-top-off-bad-im-now-believer.html

 

You know your overfilling when gas shoots out of the side of your car OR if you manage to put over 12 gallons into the tank.

You may also know after the fact, if you see the check engine light come on with a bunch of exclamation symbols and stuff.

 

Because of the bladder in the tank, the amount you can put in the tank varies with temperature (warm weather, more fuel; cold weather, less fuel). If you fill the tank until the nozzle clicks off, you won't "overfill". I usually give one squeeze of the nozzle after the initial shutoff. If you do overfill the tank, you can damage the bladder which will cost $$$$ to replace.

 

No, you're good, assuming that you did not stand there clicking the nozzle on and off repeatedly after it shut itself off.

 

See my posts in the thread "145 MPG?" for info on completely filling the tank.

Executive overview - don't do it. It can destroy the fuel tank and cost you upwards of $400 to replace it.

 

I don't think it's as fragile as the paranoia here suggests. To be safe though I never put more than 1 (one) gallon of gas in my Prius at any given time.

With regards to the bladder the bladder is friendlier on the environment. In a rigid tank there's either air from the atmosphere or gasoline taking up space. When you use fuel with a rigid tank air is replacing the volume of fuel you use. When you're empty your tank is full of air. When you refuel you're pushing air out of your tank as you put gas in therefore releasing fumes into the atmosphere. With a bladder this effect is reduced since the bladder is scrunched (technically term) together reducing the amount of air that has to be drawn into it to replace the fuel you used.

Mike

 

Now you guys have scared me. I am in Oregon. It is illegal to pump your own gasoline here.

So, even though I have always told attendants not to top off the tank even before I had a Prius, they still do half the time....

 

Topping off actually isn't a problem. It takes a long time to "top off" to the actual absolute full mark (fuel seen in filler tube). I've done it a few times, and it took perhaps 15-20 top off tries. What I suspect they are doing is in effect waiting for the bubbles to go away and replacing the bubble volume with fuel. There is still a lot of room before it's really FULL.

If you overfill, the tank doesn't "burst", what happens is the fuel expands when it warms up (it's stored in underground tanks, at about 50F). The expansion increases the volume about 2.5 litres (assuming 50F to 80F and 45 litres of fuel). If it's already full, this extra volume is forced into the vapour recovery system (carbon canister) which has an overflow tube that dumps air (if working correctly) into the volume between the bladder and the steel tank. If you have absolutely FILLED the tank, you will be "venting" gasoline into that space. This will eventually corrode the fuel system components, and even before that will quickly trigger a sensor that is there to detect if the bladder is failing. You get lots of red lights flashing on the dash!

 

Use a different service station next time? I'd bet that opening the door and yelling "WHAT THE F!!CK DO YOU THINK YOU'RE DOING!?!" works pretty well also.

 

Yeah I'd have to agree.

On the rare occasions when I'm at a full-service station, I say "fill it with regular, please do not overfill." So far I haven't had any problems -- when the pump shuts off they take the nozzle out and that's it.

If they ever did try to top it off I would yell at them to stop immediately. Then I would explain what would happen if they overfilled, including how I would refuse to pay for the gas that had spilled all over the ground and how I was going to charge them to have my car washed. But that's just me.

 

here's what's in your fuel tank, so you see what it's about.
http://priuschat.com/forums/prius-technical-discussion/30593-gas-bladder-exposed.html