2005 Prius screen isn't accurate!!

Your choice. But after four years of reading and sometimes participating in fuel range and low fuel discussions on PriusChat, I wouldn't do it right away in a Gen2. Especially in cold weather.

Pay attention to the fuel gauge, and if the last bar starts flashing, refuel immediately. Before pushing farther, build up some experience with how much fuel is needed at the various low marks, and determine whether or not your car has some consistency. Only after that, and when you can test is a fairly benign situation where running dry is not hazardous and not seriously inconvenient, should you test the very bottom regions of your fuel tank.

And do note that a few unlucky Gen2 owners have run out of gas with one bar still solid, and a very few with even two bars showing. But these cases may have been associated with a calibration issue that can be fixed.

I very much like being able to count on 50 miles past the flashing bar on my car, but mine is a newer model without that rubber bladder.

 

There's a reason we call it a "Guess Gauge". As a rough calculation figure each bar as a gallon. Dividing the mileage by the bars should get you close to the displayed fuel economy. Dividing the miles n]by the displayed FE should get you close to the number of bars used. The only time to believe the gas gauge is when it reads empty.

At 2 pips look for gas. At 1 pip consider buying gas. At the flashing pip buy gas now. Your confidence will build as you drive. If you run dry, don't coax the car. A discharged traction battery, tow to the dealer, and expensive recharge (at best) will be the result.

 

My personal experience. I always refill after the flashing bar comes on. Have never run out of fuel. Have sometimes "pushed" it to almost 600 miles before filling up.

Warm weather mpg's in the prius vs cold weather mpg's are quite different. During summer months I will sometimes average 52.5 vs. very cold weather 42.5.

Good luck with your new Prius and let us know what you think as you gain more experience with this wonderful vehicle.

 

I also agree that the guess gage is just that, it is a guess. However, I also agree that when you get to two pips, it is time to think about fuel. Until you get used to how the Prius works, I would suggest you fill at two pips. Then after a while you will get more accustomed to it, you can try going further into the tank. With the bladder, you CANNOT expect to put 11.9 gallons in. I think the most you will ever be able to put in is around nine (9) gallons, or a little more. For the record, if you do ever run out of gas you will need a minimum of three (3) gallons of fuel to get the Prius restarted. Adding just a gallon or two will not be enough for the Prius to start once it runs out of fuel.

I filled today with two pips showing and it took about seven (7) gallons. I travelled 350 miles that was mainly city on that tank. That tells me I probably could have gone another 100 miles if I so chose, however even after the two years I have been driving the Prius I just don't want to take the chance to run out of fuel. As was mentioned above, if you run out you risk possibly discharging the traction battery and having to have the Prius towed and then recharged. The Prius is NOT designed to run on the battery only. Once you get used to it, you will have a better idea of your comfort zone. Many do run down to the flashing pip, however other's have reported running out with 1 or 2 pips.

Enjoy the mileage of the Prius and keep learning about it. In time you will have it figured out. It truly is unlike a conventional car in many ways.

 

As a recent Gen II owner, I've only had the pleasure of filling the tank twice so far. Both times I did it with two pips, and both times it took only 6.5 gallons of fuel. This next tank I will take to one pip, but that's as far as I'm willing to go until I get more experience with the Gen II.

As you all said already, I feel I will get to learn more about the gauge and what it actually means as I own the car for a longer period of time.

 

It's safer to use the guage and fill it up when you have 2 pips, because you never really how much gas you have in the bladder after you fill it up. To experiment you could fill it up a one pip, see how much gas it takes and if you are brave you can wait until one flashing pip and fill it up, if you are really curious.
I see you are in Chicago, trust me, your gas tank bladder will hold a lot more gas in July than in Early March.

 

I only drive my Prius after all the salt has washed off the roads and I have no problem putting in 11.6gals after driving awhile on a blinking pip. I never drive it in winter so as they say the cold temp will not let you put in a lot more.

 

You should fill up when the gas gauge indicates you are low on fuel. Filling by number of miles is foolish as driving circumstances frequently change. Weather (especially temperature), distances, speed, driving style, et al.

 

I've been having this same problem with My 06 Prius I just purchased. I live in Maine so the weather here has been erratic, but my gas gauge seems to go down fast after a fill up. At first I thought I had a gas leak, but I didn't see any leaks. I guess it must be the cold messing with the gauge. It seemed like my Dodge Ram V8 was getting better MPG.

 

I filled up yesterday, drove a bit - went down 1 bar. This morning I have all bars. Must be the cold.

 

What you are reporting is typical of a new owner of a Prius in the winter time. Cold temp's do affect the MPG. Once it get's warmer and drier, your MPG should improve.

Also, take the time to research the tips and tricks on how to achieve the best mileage YOU can. First and foremost, remember that your mileage will vary. With that said, there are some things you can do that should help you to increase your mileage.

If you are simply driving the Prius like any other car, you will not achieve the high number's that can be achieved with the Prius.

For more information, see here:

Hypermiling with Pulse and Glide - How to use Pulse and Glide - Pulse and Glide in a Hybrid

There are other's tips and tricks available that should help you. One thing that is very easy to do is to simply raise the air pressure in the tires. The Prius tire pressure placard specifies the "minimum" air pressure for the tires on the car. 35 Front 33 Rear (Gen 2) Quite a few here on this board will run their tires at 42 Front 40 Rear. What ever pressure you choose to run will be Ok as long as you do not exceed the maximum pressure that is stated on the sidewall of the tire. Also, there are different types of tires today. The Prius gives better mileage if you have what is known as LRR (Low Rolling Resistance) tires.

F8L posted a list of these here on Prius Chat. If you need tires now or in the future, you might consider LRR type tires as they should help your mileage.

Low Rolling Resistance replacement tires: Current List | PriusChat

Here is a very good explanation of P&G by Wayne Gerdes.

http://www.cleanmpg.com/forums/showthread.php?t=1224

Good luck to you and enjoy your Prius.

 

Learn how to drive the car more efficiently and learn how the Prius works before you start modding. You could harm the car if you don't know what you are doing. Efficient driving will increase mpg much more than a grille block anyway.

 

My first fillup with our recently bought '05 was at two pips and it took about 5.8 gals and showed full on the gauge. The second fillup which was last weekend after about 290 miles, and down to a flashing single pip, took 7.2 gallons and was showing full on the gauge. I guess that bladder does make a pretty big difference in tank capacity in cold weather.