Posted by firstname.lastname@example.org on June 23, 2005, 2:40 pm
This is still my 'first' tank of gas, meaning the first one I paid for
(I bought the car with a full tank of gas from the dealer), so I
haven't tried using different nozzles. I went to a Gate station here
in Jacksonville (Southside and Touchton) to fill up. I do recall that
I did top off to the nearest nickel when I filled it up. I'll try not
topping off and seeing how that goes. However it seems a bit strange
to me that something like that would affect my MPG. I do notice that it
takes a while, about 100 miles or so, for the gas gauge to show any
change. As soon as it does change, the tick marks start disappearing
more quickly. I wonder why Toyota designed it that way instead of
showing the actual level of the gas remaining in the fuel tank.
Posted by Staff on June 23, 2005, 4:32 pm
You are right, of course, that this issue will NOT effect mileage. The
Prius doesn't take gas very quickly, probably because back pressure causes
some overly sensitive pumps to shut down prematurely. The BP station where
I regularly fill my Prius works perfectly every time but I once stopped at a
station where I couldn't gas up at all from one pump. I gave up, switched
to the next pump (wasting some money on higher octane) and it filled
My gauge works as well as the one in my Explorer. With the Explorer, the
reading varies considerably depending on how level the car is. It read low
when parked nose down and high when parked nose up. For the most part, I
ignore the gauges in both cars until they indicate 1/4 full. At that point
I fill the Explorer knowing my range will be quite short. With the Prius, I
start thinking about filling it over the next couple of days. :-)
Someone put me onto the 'rule of 10's' and I found this to work very well.
Don't reset your mpg reading between fills. Multiply the mpg reading by 10
and fill when the miles on that tank approaches the product of that
multiplication. So, then, if you are averaging 48 mpg on a given tank, gas
up at or a little before you have driven 480 miles on that tank. My best
tank so far ran 55 mpg and I gassed up right at 550 miles with a gallon and
a half to spare.
I'm only running 48 on my current tank because I've had several short trips.
I only get 35 mpg for the first 5 minutes after starting the car so a series
of short trips can dramatically reduce fuel economy. FWIW, the same is true
for my Explorer.
Posted by Andrew Turner on July 19, 2005, 4:23 pm
The Prius also has an "inflatable" tank - which I think causes the gas
gauge to change non-uniformly across the tank.
For me, on the first 2200 miles I've noticed that I can go about 300+
miles on the first "half" of the gas gauge, and then about another 150
on the last "half".
This is annoying, and the gas gauge blinks when I have only used about
9.5 gallons - where I *should* have about 2.4 gallons left, that's
almost 120 miles!