Returning home from South Dakota I stopped to gas up in Sioux Falls. I set the pump to the slowest setting, as I always do, cleaned the windshield and rear windows, and waited. I thought the gurgling noise was odd, but before I could react, gas was coming out. I pulled out the pump handle and got the gas cap on without getting any gas on myself. I'd guess I spilled between half a cup and a cupful of gasoline. Grump!!! I presume Toyota would not design the fuel system such that overfilling would cause any permanent damage, but I was seriously PO'd. There were two bars showing before I filled up, and I think I probably had burned something like half a gallon since the gauge went from 3 bars to 2. I pumped 9.6 gallons. I went 211 miles before I noticed that the first bar had gone out. I was keeping an eye on it, but not constantly, so I'm going to say that I went approximately 200 miles from full-to-the-neck to 9 bars showing. This will be my personal record for miles on one tank. As a postscript, based on eyeballing the 5-minute averages, I was generally getting around 50 mpg on slow-speed highways (55 mph), and around 44 to 46 mpg on high-speed highways (75 mph). I'm pretty happy with these numbers.
I would say it would be better to pump at the medium or full setting, to allow auto-shutoff to occur. I pump at full pressure then add .5 gallons or so usually. Last tank, I went 180 miles before the top fuel bar went out. The remaining bars went out every 40 miles or so.
spit-back... maybe not! i think you just confirmed my prior comments.... in this situation, the nozzle never cut off at all, and you caught it as the tank and filler neck filled right to the brim and overflowed. that's not spit-back! plus, the fact that you went so far before the first fuel gauge bar moved... tells me that, just as when i "top off" my tank, you'd put an extra gallon or two above the point where the nozzle would have cut off, and until that fuel is consumed, the "tank" .... the part where the sensor for fuel level is.... doesn't start emptying at all! nobody has reported spit-back, that i've seen, that happened a few seconds after the nozzle was removed from the filler hole, right? i'm betting that any such spitback was due to a very slow fill rate that never triggered the nozzle to shut off automatically!
Just wanted to add another data point: At my last fillup I set the pump to its lowest setting and went to check my oil level. After a minute I heard a splashing sound and saw to my horror that gas was pouring down the side of the car!! I quickly shut it off, screwed the cap on, and tried to clean up as best I could, but gas kept dribbling out even with the cap on tight. It was still coming out when I got home a few minutes later. I had to close a rag inside the gas door for a few minutes to soak up the last of the leakage. It's possible it was a faulty nozzle or that it would have shut off if I'd used a higher setting (I wish I'd found this thread before my disaster), but I personally will never trust the auto-shutoff again.
We have a pattern developing here: auto shutoff doesn't work so good on the Prius with the pump handle set to deliver at the minimum rate. Set it to the *maximum* rate (or to the highest rate that does not result in an immediate shut-off) and everything should be fine.
A clarification: After I pulled out the nozzle, gas continued to burble out of the tank. It was still trying to burble out as I jammed the cap on and screwed it tight. However, unlike LungCookie's experience, in my case no more gas came out once the cap was on tight.
Follow-up: I just refilled again for the first time since my overfill. Because of the screw up I don't know how much gas went in last time, but the tank lasted 665 miles at 49.6 MPG, so it must have been about 13.5 gallons. Add that to whatever was left over in the tank and that's a whole lot of gas for an 11.9 gallon tank. I hope nothing was damaged. :| This time I filled it using the highest pump setting (at a different station... with my hand on the handle!) and it shut off without incident at 10.57 gallons.
*I* don't think you love your car at all! If you loved it, you'd drive it more! A month between fill up... PUH-LEESE! ! ! On the other hand, *I* L-O-V-E my Prius because it turned 5,000 miles today and it's a couple days shy of being a month old! :mrgreen:
