How much gas is too much?

<div class='quotetop'>QUOTE(Maytrix @ Jun 18 2006, 04:42 PM) [snapback]273182[/snapback]</div>

Wow. I've yet to put in 10 gals even with trying to top off the tank.

 

Hmmmm....Even though the bladder is flexible, I would more readily suspect that the station's pump is off. Was this your regular gas station? If you track all your fillups (and MFD MPG) on a spreadsheet, you'll see easily enough in the next couple of fillups whether or not you actually got 12 gallons of gas.

 

I had a similar event. I drove about 200 miles, and the consumption screen display showed an average mpg of 53. I figured about 4 gallons ought to fill it. I set the little catch on the pump handle for automatic, and it pumped about a gallon and shut off. I put it back on again, setting the little catch so it would fill automatically. I then went into the car and recorded my mileage, reset the trips, and was going to write down how many gallons it took when I noticed that this thing was still pumping at 6 plus gallons. It hadn't shut off yet. I manually shut it off, and removed the nozzle (a nice, tight fit). Gas then acutally bubbled out in quite a stream, down the side of the car and onto the pavement.

Perhaps it was a rare event, but it sure scared the you-know-what out of me.

 

<div class='quotetop'>QUOTE(Maytrix @ Jun 18 2006, 04:27 PM) [snapback]273200[/snapback]</div>

I'm a bit brain dead at the moment, but I think there's some kind of vapor/emissions canister at the top of the gas tank that can be compromised by getting gasoline in it when you fill it too full. Maybe galaxee can ask her husband about it since he's a Toyota tech. If this canister was damaged, it would be gas station's fault for having a pump that doesn't shut off when it should. I hope you kept your receipt showing 12 gallons, because that would be good proof that the pump was faulty (since we have an 11.9-gallong tank).

 

I,ve had that happen a couple of times. Too many gals. & gas spitting out. I have 6,700 miles on the car with zero neg. effects. I wouldn't lose any sleep over it. It was the particular pump the times it happened. I did notice that @ the next fillup I got much more MPG than what the computer showed.

 

I have seen pretty much the same thing, I think I stopped putting it in at 11.9 or somewhere around there. It was a hot day and I had been driving on the last square for 30 miles or so. The pump being inaccurate seems unlikely.

A normal fill up for me is usually between 7 and 10 gallons.

 

I've also gone slightly over 12 gallons once on a long trip. Unusual but not impossible

 

<div class='quotetop'>QUOTE(MarinJohn @ Jun 19 2006, 09:41 AM) [snapback]273389[/snapback]</div>

Think you guys are lucky you weren't sitting on the side of the road wondering where to walk to for some gas like I was a while back.

 

<div class='quotetop'>QUOTE(Maytrix @ Jun 18 2006, 05:42 PM) [snapback]273182[/snapback]</div>

Yes.

That rather significantly shortens the life of the vapor canister (a piece of cleansing equipment connected to the fuel tank). Rather than dealing with vapor, it got flooded with liquid. Do that enough times and it will eventually fail, causing an emissions system warning. At that point you'll have to replace it.

 

The "worst" i'd had was doing the old "wait til it clicks off, than add slowly" routine. I didn't record the actual amount used, I just know I had fuel splurt back up and out for a few seconds.

Personally with the Prius, I'd have preferred either a US "standard" 15-18 gallon tank to the funky 11.9 bladder system. Assuming this, I would only realistically fill up once every 3-4 weeks or so.

Does anyone know if the bladder system was mandated by US law or was it some sort of way to reduce polution?

 

<div class='quotetop'>QUOTE(satsuke @ Jun 20 2006, 01:33 PM) [snapback]274173[/snapback]</div>

My guess is that it was to save weight !!!

 

<div class='quotetop'>QUOTE(B Rad @ Jun 20 2006, 01:48 PM) [snapback]274186[/snapback]</div>

I think i have read somewhere on this forum and in other places that the reason for having the bladder was to reduce pollution. Since the bladder contracts, it reduces the amount of gas vapors in the empty space in a nearly empty tank, thus reducing emissions.
At the time of taking delivery of my car, my salesperson told me spefically not to ovefill the tank. He said that one it clicks off (when on automatic fill), at the most maybe we can round it off to the next 10th of a dollar (as some people tend to do), but never the to the next dollar. He said that overfilling could cause gas to leak out and damage something in the sensor mechanism (I do not remember exactly what it would damage).

 

Overzealous fillling of the tank leading to a spill negates the low emissions of the Prius for a **long** time.

I fill up on the slow flow rachet on the pump handle, usually 9.5 - 10.5 gallons from the 'add fuel' warning light, and get 500 - 600 miles between fillups. More than good enough, and no risk of bubbling over.

If you want to push the envelope of how far a tank will take the car, improve FE, rather than trying to stuff the tank.

 

<div class='quotetop'>QUOTE(EricGo @ Jun 20 2006, 03:37 PM) [snapback]274247[/snapback]</div>

One could argue Toyota is practacing deceptive marketing with the prius in this case.

I should be able to get the advertised 11.9 gallons in the tank, I can't.

I should be getting 60 city, 51 highway. I get 40 - 45 city and as rated highway.

I do not drive my Prius like a much larger car, no jackrabbit starts, easing the throttle in EV whereever possible, not speeding excessively, no high AC usage.

These facts do not explain a 33% varience between advertised and actual.

As far as overfilling the tank, I have never seen a situation before where the tank had become pressureized in this way. As far as why doing an extra session for gas ,. this was before a long trip ,. the difference between gassing up on the way or making a through shot.

As far as 550 - 600 miles per tank ,. show me, in my car ,. 500 miles on a tank is the best I've done so far ,. note I've only had it a month and have put 2000 miles on her so far.

 

<div class='quotetop'>QUOTE(satsuke @ Jun 20 2006, 02:26 PM) [snapback]274272[/snapback]</div>

Toyota is advertising the only numbers it is permitted to advertise by law, the EPA test results.

Many of us get considerably better mileage than you do even when use the air conditioning. It was in triple digits here over the past weekend and my MPG on this tank, with 440 miles on it, is about 52. I set the a/c at 76.

The EPA urban test is modeled on Los Angeles area driving; perhaps that explains my results. Seriously, with only one month and 2,000 miles experience, you have yet to master the optimal driving technics to maximize your mileage.

 

Satsuke: If you look on the epa sticker, you will see a *range* of fuel economy that the epa thinks most people will fall into. You are in the zone. For a lot of people, doing even better is a matter of changing driving habits; for some, the local conditions and driving routes conspire against it.

Try not to be so quick to find someone to blame. If you are interested (and I hope you are !), read some of the excellent threads around here explaining how to maximize fuel economy. You will improve, and I promise you, the results will be a **whole** lot better than your previous vehicle.

Yeahh, the tank bladder prevents a complete fill. If that is your major peeve, you will *love* the car