Some fuel-related display questions

I've got a few questions related to fuel read-outs on my displays:

1. I recently filled up with gas for the second time in my new '06 Prius. The "miles travelled" reset to 0 as the instructions indicated it would. However, the MPG number apparently did not begin calculating MPG for the new tank only. At the end of the previous tank of gas, I was getting 54.9 mpg according to the MFD here in warm Albuquerque. After I filled up and began driving, the MPG figure remained at 54.9, and it only changed in .1 mpg increments, and very slowly, over twenty miles or of mixed city and highway driving. It did not change quickly and dramatically as you would think it would at the beginning of a tank if it were only calculating the milage from the new tank of gas. The manual states that the MPG number "indicates the average fuel consumption after being reset," (p. 168) but that does not appear to be what happened. What is your experience with the MPG figure?

2. I filled up about 10 miles after the last dot on my fuel gauge display started blinking. I was able to get about 8.9 gallons into the tank at a temperature of about 80 degrees. I understand from reading other threads that there is some variation in the amount of fuel that that the bladder in the tank will take, that the amount is related to temperature, and that it may vary up to about a gallon. Still, I must have had 2-3 gallons left in my tank when that last dot started to blink. :blink: Is there something wrong with my fuel guage, or is this normal? If this is now my fuel gauge works, can I rely on there being 2-3 gallons left when the last dot begins blinking?

3. How accurate is the average fuel consuption shown on the MFD? Although I only have a small sample so far and there are various factors that could account for the discrepancy, my display is about 3 mpg higher than my calculated mpg.

- Richard

 

<div class='quotetop'>QUOTE(kdmorse @ Apr 23 2006, 09:15 PM) [snapback]244128[/snapback]</div>

That comports with my experience, and I actually prefer it that way, but they need to rewrite the manual to reflect this. The description of this item in full reads:

"Indicates the average fuel consumption after being reset. When the "Reset" switch is touched or more than 10 L (2.6 gal. 2.2 imp.gal.) fuel is supplied, the average fuel consumption is reset."

It apparently is not being reset. It's bad enough that the salesman at my dealership is a font of misinformation, but I would like to be able to rely on the manual. At least I have Priuschat!

I don't understand how that bladder works, but I wish it consistently took the advertised 11.9 gallons. Two or three gallons less is a BIG difference. I don't like having to stop for gas more often than necessary.