How many gallons in a reserve tank when the last pip start blinking?

One consequence I can do without: walking back up the highway, looking for a gas station. Who had them? Anyone who put off refueling just a bit too long

 

Sure thing if you want to measure you need to have some petrol in your trunk otherwise youre stupid m... hehe

 

Well, prior to reading this thread, I didn't know there was a bladder in the fuel tank. All I knew is that, if I waited for it to go to one pip, then waited for that pip to start flashing, then waited for the fuel light to come on, when I filled up, I would add about 8.5 gallons. The specs in the user manual say it's an 11.5 gallon tank (without mentioning it's a bladder and therefore inaccurate, and the fact that they put a decimal value indicates that the figure they give is somewhat accurate to that decimal place) so that's 3 gallons still in the tank (theoretically). That's a 25% error margin, which seems pretty lame to me, even for a flexible bladder

 

Yep, it's lame, but it is what it is.

 

Except for one car, that lameness matches or is fairly close to all the other non-hybrids I've owned.

The one exception had a fuel gauge with much less error. Unfortunately, as I discovered the hard way, the error it did have was of the opposite polarity.

 

I believe the owners manual states there is 0.9 gallons of fuel when you get the low fuel message. I've put 105,000 miles on my Prius and always wait to fill until I have one bar left. I've run out of fuel once and was within 100 yards, or so, of the gas station. The fuel gage gets erratic behavior on the very hot and very cold days. I think thats why most So. Cal. owners state to fill up when your at two bars. If you never want to run out, then I suggest you follow their lead.

 

The 2006 Prius fuel tank definitely won't be able to draw 11+ gallons from the tank. No need to run it dry to verify. Been there, done that. 10.6 gallons is all I could fill, but that depends upon the sensitivity of the auto shut-off on the gas station pump. Owners in So. Cal. will probably not be able to fill more than 10 Gal, because of the pump sensitivity issue.

 

I follow a rather simple method. I fill up the tank and will only base my range on 10 gallons of fuel. In a sense, if the car is returning an average of 51 miles per gallons; I consider my range to be 510 miles. I then just look at the distance travel on that tank to determine when I need to refuel. Since the Gen II Prius uses a fuel bladder, the tank suffers from variable capacity due to outside temperature.

A good example is the fact that I drove this weekend from Keller, TX to San Marcos, TX and back, in one tank of gas. The fuel light came on 88 miles from home just south of Waco, TX. I continued to drive the car until I got home and refueled it this morning. The car only took 10.159 gallons of fuel (capacity is published as 11.9 gallons). The reason I felt comfortable driving the 88 miles with the fuel light blinking was simple. I determined that since I was getting 52.6 miles per gallons, my fuel range should be 526 miles if I use 10 gallons of fuel. I knew the total distance for the trip was going to be 492 miles, giving me plenty of room to spare. Sure enough, when I refuel the car it took just over 10 gallons to refill it. Since the temperature when I got back home was 20 degrees warmer than when I left, I was able to put more gas on the car when I refuel this morning.

 

nice!! :d

 

my range estimate is 10 gallons on Classics, 11 on the 2010's. without the bladder, its easy to do that. i dont top off the tank so i am losing about ½ a gallon or so i am guessing.

the other thing is i get gas when its available and only use Costco unless out of town or something so i rarely get to that 11 gallon mark but have done up to an estimated 10.6 gallons or so and i have never run out of gas in any Prius. (my SO has done it twice) but she is not proactive in monitoring that kind of stuff and does not get gas

 

I may start changing when I re-fuel based on this topic..
I just got the best '1 pip' mileage - 180 miles and finally lost a pip..

Usually only get around 85-90 miles.

 

It's been awhile since I've been to this site, so long, I lost access to my account.......

For what it's worth on this subject, I use to be a mechanic more years ago than I care to remember. However, even then, most fuel pumps were electronic as in most cars today. Running the fuel extremely low or out was great for business but bad for the vehicle. The fuel running through the pump and in the tank was necessary for the longevity of the pump because it provided lubrication and cooling to the pump. This helps prevent wear and tear on the pump. Even a tank low on fuel can cause this type of damage to the pump as the fuel can be displaced to one side of the tank during a turn, accelerating, or braking, starving fuel from the pickup tube/inlet for the pump.

Of course when the pump completely fails, you'll know it because the vehicle won't run. But if the pump doesn't completely fail, typically, fuel pump pressure can drop and the effectiveness of the fuel injection system declines, which can lead to other problems including less than optimum fuel economy......... one of the reasons I think many people buy the car.

As some folks have mentioned here, you may want to fill the tank while a few bars remain on the gauge.

 

Well, if you subtract the number of miles on your trip odo from the product of the gallons you put into the tank last fillup times the MPG you got last tank, you can usually make a pretty good guess as to how many miles you can safely drive before refilling.........