Another gas gauge question

when you get to one pip - fill it up with gas.

when you get to one blinking pip - FILL IT UP WITH GAS RIGHT NOW!

if you think to yourself, 45 mpg, 11 gallon tank, 495 miles on a full tank, one pip, 400 miles, no problem - can go 75 more miles - YOU WILL RUN OUT OF GAS!

<div class='quotetop'>QUOTE(dsharp88 @ Oct 11 2007, 08:21 PM) [snapback]524312[/snapback]</div>

 

My 2005 echoes the same experience you have: I fill up with 2 pips, but when I fill up, I only put in about half the 'tank's' capacity.

As the Prius is a bladder and not a gas tank, I'm not sure in extreme temperatures, I get the full 45 litre capacity anyway. And I've read enough posts to tell me never to run out of gas! So I play it safe, and fill up when I get to 2 pips.

 

Clint Eastwood:

....Are you feeling lucky?....

 

A few important things with a new Prius (meaning a new and stiff fuel bladder):
1. The gas gauge is not linear. It is not as precise as you want it to be. (This is true in all cars, but Prius owners are a little gas-gauge obsessed!)
2. You will not get the car to a consistent fill level until the bladder gets loosened up. The gauge may say full every time you fill it up, but after much experimentation (and running out of gas once) I concluded that the total fill level I could get into my Prius varied quite a bit for the first months.
At first, I convinced myself that the gauge was just wildly pessimistic. I drove 60 miles with the last pip flashing and only got 10 gallons in it when I stopped for gas. So the next time it got low, I ignored it for awhile, but *ran out* 45 miles after it had started flashing. And then, with much fiddling, after I rolled into the station on battery power, so obviously the tank is bone dry, it would only take 10.9 gallons.
3. The bladder does not seem to reach its rated capacity right away. It takes some time and use (and maybe heat) to loosen up. So if you can never put more than 10 gallons in it at first, don't assume like I did that there must be 1.9 gallons left hiding in there. You will run yourself out

Maybe as the bladders loosen up, you can push the envelope more reliably. Since then my Prius saw its first hot weather and I've put as much as 11.2 gallons in it. But after running out of gas and barely making it to the station before running the HV battery down, my enthusiasm for pushing the limits has diminished.

 

I'll probably get some criticism for how/when I fill up my tank...

Normally, I'll fill up once I've used about 10 gallons of gas. Multiplying my average mpg by 10 will tell me when that is. So if I'm averaging 53.3 mpgs, I'll fill up around 533 miles. A couple weeks ago I was averaging 53.5 and I filled up at about 550 miles. Also, knowing that I've burned about 10 gallons, I'm always able to pump in about 10 gallons with no problems. At most, I've probably done an additional 2 clicks past the auto shutoff, but still resulting in just over 10 gallons.

Note that I've never ran out of gas, and the most I've ever gone on a flashing pip is about 100 miles before I filled up. There's been times when the last pip began flashing very early and times when it started flashing really late based on my mpgs and last fill-up. At this point (been an owner since August '06), I really just ignore the low fuel warning and go off of my mpg calculations. It's worked for me, may not work for you.

 

<div class='quotetop'>QUOTE(pricoaster @ Oct 14 2007, 07:41 PM) [snapback]525640[/snapback]</div>

IMHO... the fuel tank is kinda like the climate control system. Don't try to figure it out, you will drive yourself nuts. If you get to one pip, fill'er up. If you're cold, hit the temp up arrow, if you're hot, hit the temp dn arrow. Keep it that simple and you will be happier.

 

I must be the minority. I have always used ten times my current average MPG as an estimate for how many miles I can go. Perhaps because this is conservative (10 gallons) I've never had a problem.

 

Hatter--is that your actual Heads Up Display? Because mine's just the opposite...

 

I go to 2 pips or 375-400 miles, whichever happens first as I pass a station. I do 450 miles a week just in commuting (no side trips), and I've never been "brave" enough to go a whole week before stopping, though it could possibly be done...in theory. I'm averaging just under 52, and usually put in 7-8 gals at the above mileage. I've only had the blinking single pip once, and bought gas immediately.

 

Can you explain that to me????? I have had my Prius for 2 weeks now. I read in the manual that it has a 12.9 gallon gas tank. I'm averaging 44 mpg. The manual also said that when the last pip starts blinking, I have about 3 gallons left - that's over 130 miles left to go.

So today it started blinking and I ran it 50 miles and ran out of gas. It went on total electric then ran out of juice and I barely coasted to a gas pump. When I filled up, it only took 11 gallons by over filling. So what's up with that?????

 

Here is another recommendation for filling up at two bars/pips.
This will accommodate factors such as outside temperature and bladder tank capacity.

 

<div class='quotetop'>QUOTE(flutterby4x @ Nov 8 2007, 07:08 PM) [snapback]536931[/snapback]</div>

The flexible bladder inside the tank (used to help reduce evaporative emissions) means that the actual capacity is almost always less than the maximum capacity given in the owner's manual. The "guess" gauge has one reliable function: when it says the fuel is running low, it really is running low. You cannot presume to know how much farther you can still go based on how far you have gone and the reported MPGs to that point. As you and many before you have discovered, people who try this run out of gas.

When the gas pump shuts off automatically don't try to top it off. It is likely to overflow. And sometimes you find certain gas pumps in which the automatic shutoff is not very sensitive, and they can overflow also. So when you find that a pump has put in 10 gallons or more you should probably manually stop at that point and not use that pump in the future.

 

Thank you so much for that explanation!!!! I had no idea there was a special way of storing gas. I will try to dig up more on that. I really appreciated the information!


<div class='quotetop'>QUOTE(richard schumacher @ Nov 9 2007, 07:30 AM) [snapback]537245[/snapback]</div>

 

Pay particular attention to what "Walt " has to say. It is not fun running out of gas. One pip get gas / Flashing pip get gas NOW :lol: