filled my tank for the first time today and.....

Congrats on your 50+ mpg

 

Yeah grats on the 51 tank. It should only go up

 

<div class='quotetop'>QUOTE(KateBell1977 @ Sep 8 2007, 12:57 PM) [snapback]509128[/snapback]</div>

Congrats! on your first 50+! I just got my new prius about 4 weeks ago and filled up my tank for the third time and got my first 50+ reading on my second tank full.. I got 51.2, 498 miles. I filled up my tank yesterday and got 56 mpg with 451 miles. Which to me is strange because i got more miles on the last tank with less mpg, but higher mpg with less miles on this one... I always fill up when i see it blinking. This last tank was all going backroads to work, the other tank was all highway. anyone know why?

 

<div class='quotetop'>QUOTE(KateBell1977 @ Sep 8 2007, 12:57 PM) [snapback]509128[/snapback]</div>

Congrats! on your first 50+! I just got my new prius about 4 weeks ago and filled up my tank for the third time and got my first 50+ reading on my second tank full.. I got 51.2, 498 miles. I filled up my tank yesterday and got 56 mpg with 451 miles. Which to me is strange because i got more miles on the last tank with less mpg, but higher mpg with less miles on this one... I always fill up when i see it blinking. This last tank was all going backroads to work, the other tank was all highway. anyone know why?

 

<div class='quotetop'>QUOTE(esears1 @ Sep 12 2007, 03:51 AM) [snapback]511154[/snapback]</div>

welcome to the world of the Prius bladder and inconsistent fills. With winter and cooler weather coming on, expect it to get even worse. The first time you fill on a cold day and then get some warm weather for the next fill and scream because your mileage has tanked into the high 30's, only because the bladder had shrunk. I average mine over 5 tanks to get a realistic average.

 

I don't have a bladder and I find the computer very accurate.

Congrats KateBell on the great first tank. You did good.

 

Thanks for this thread. Today was my second fill-up on my used 2006 Prius. Sounds like all of you have combated the same issue that I am now confronted with. Namely, gas pump stopping prematurely at about 7.8 gallons. I am able to squeeze in a little more (0.8 gallons today and 1.5 gallons two weeks ago) fuel into the tank by manually fueling the last bit at the minimum speed with the spout as far out of the filler neck as possible.

 

Please be careful. How are you sure that the pump is stopping prematurely? As inconsistent as our gas gauges and gas bladders in the tank are, even if the gauge is down to one pip that 7.8 gallons may be all the fuel it needs. I know that figure is very similar to the results on my car.

That extra fuel you are trying to squeeze in there may well be akin to topping off, a practice that can damage the vapor recovery system. From what I understand, that can be a very costly repair.

 

Hey thanks for letting me know about the vapor recovery issue presented by overfilling the gas tank. I was unaware. That is why I love priuschat so much (always new and useful info).

Yesterday, when I filled up the following occurred:

1.) I did not go the gas station until the last bar on the gas gauge was flashing;

2.) After the gas pump clicked off (and I concluded the transaction), I restarted the Prius and found that all the gauge bars EXCEPT the last one was lighted up (it appeared that the Prius was only 90% full);

3. As a result, I restarted the gas pump and pumped in another 8/10 of a gallon.

Question 1: does Gen2 fuel tank really have a capacity of 11.9 gallons (what it says in the manual)?

Follow-up comment: during my first tank of gas in this used Prius, I averaged 44mpg according to the MFD and traveled 418 miles according to the odometer. 418 miles/44mpg=9.5 gallons. Thus, my goal at fill-up was 9.5 gallons. Where am I going wrong here with regard to goal for what the number of gallons should be in refueling?

My initial goal for refueling was 9.5 gallons but I cumulatively only pumped 8.6 gallons (7.8 gallons plus 0.8 gallons) in this second refueling.

 

Where you're going wrong is both depending on the MFD mileage display and attempting to hit a specific target as to the number of gallons you're trying to put in. The tank ideally holds 11.9 but the flexibility of the bladder affects the capacity a lot. It may hold as little as 10 gallons if it's not fully flexible at the time (especially very cold weather). Additionally, the MFD MPG is usually overstated (not always) so it really is no help guessing how much you will be able to put in.

The best thing to do is to keep track of it with an app. I personally keep track with a notebook in the glove compartment that I then key to fueleconomy.gov and fuelly.com. You will not get a real sense of your true MPG unless you look at the mileage over multiple tanks.

I'm not sure about how much you drive and how often you really need to fill up. What works for me is to just keep an eye on the gas gauge along with the trip mileage on the screen. At 2 pips left on the gas gauge I keep an eye on it. Once the mileage hits 300+ miles (many times it's already there) I just fill up whenever it's convenient and at a station with top tier fuel at a decent price. I just fill at the slowest pump setting and stop when it clicks off.

No worry or stress. Of course, I realize it has to be a bit different for people using their cars for long commutes. It's a matter of what works for you. You'll find if you can just fill when it's convenient after you hit two pips or one pip and don't sweat the # of gallons pumped each tank you'll have a lot more stress free driving.