Question about range....

Its an 11.9 gallon tank isnt it? You have 3 1/2 to go before running out. I say play Kramer(from Seinfeld) and see how far that baby can go! Live a little! LOL!!!

Craig

 

I typically get the low fuel alarm after 500 to 530 miles, re-filling with about 9.4 gallons at an mpg lately of 54-56. It sounds like your low fuel alarm is calibrated lower than most Prii if you are only putting in 8+ gallons.

The issue of your poor gas milage is another matter. Florida ought to be a place to get great mileage based on terrain, but you might be using the A/C all the time, and you might drive the car harder due to bad Florida traffic.

 

I consistently fill up 9 ga when the fuel gauge starts flashing. It is as Toyota designed to leave about 2 ga at the bottom to cool and prime the fuel pump. No calibration problem there.

I use cruise control all the time in city driving even for short distances before red lights. I found that my foot on the gas paddle could not match the fuel efficiency that the cruise control provides. Even though I'm gunning it all the time in PWR mode, I'm still averaging 55-59 mpg and 500 miles range for 9 ga tank.

 

As per a prior post, the capacity is 11.9 gallons (US). I roughly assume that each bar represents a tad over 1 gallon of gas (1.19 gallons, to be exact). So, if you fillup at "1 bar" remaining, prior to fillup, you still have 1.2 gallons (1 bar) + 2 gallons reserve...and to first order, that's right about the capacity of the tank after your 8.5 gallon fillup.

350 miles + (3.2 gallons) X 44 miles/gallon = 490 miles. Close to the advertised range.

I'm getting over 60 MPGs this Summer, so I expect my range is closer to 700 miles. But I never let it get to zero bars, so my "comfort" range is almost 600 miles, or two weeks between fillups for me.

 

I have had the same problem for my first two tanks in my III. The gauge shows one bar remaining, the fuel warning light is flashing, the miles to empty 5 or indicates 10 remaining, and I am only able to put about 9.25 gallons. Then the tank shows full and the mathematically checked mileage is reasonably close to the 53 mph that the computer shows. It's clearly a glitch in the program. If anyone has any bright ideas, I'm all ears.

 

Penny's Dad, sneeree,

I don't know how similar the Gen II and Gen III are in the way they
calculate the amount of fuel in the tank.
(Yes, I know the Gen III doesn't have the accursed bladder, and it
appears to be irrelevant to the following any way. )

FWIW, here's what a Prius training document for the Gen II says:

"Inclination Sensors

"There are two inclination sensors located in the meter ECU to detect
vehicle longitudinal and latitudinal inclinations and to correct the fuel
level calculation. Corrections are made by the signals from the
inclination sensors and the ambient temperature sensor loated in the
fuel tank.

"The inclinometer must be reset if the customer complains that they can
only pump a fewvgallons of gas into their tank or that they run out of
gas with three or four bars left on the fuel meter. The inclinometer
must also be reset if the Prius is refilled on an excessive slope or if the
fuel gauge becomes inaccurate. Please refer to the Prius Repair Manual
for the inclination calibration procedure."

From here.

Has anyone seen a similar discussion for the Gen III fuel system?

Well, at any rate, -- and I hate to say this -- you may need to talk
to a Prius tech to discuss re-calibration as a possible solution.

 

It's not a glitch, it's intentional.

That is how gas gauges work, they almost always indicate empty with some usable amount of gas left in the tank.

A Gen3 Prius gas gauge works off a simple variable resistor that is moved by the gas level float in the gas tank, just like nearly every other gas gauge. When your miles left reading says 0, that is no more accurate then when you a regular gauge gauge needle hits empty.

Toyota has chosen to have the system indicate 0 miles left when there are approximately two gallons left in the tank. Quite a few other cars leave about the same amount of fuel in the tank when the gauge hits empty.

One thing that does help is that the miles to empty reading is well damped so doesn't respond to braking, acceleration or corners like a conventional gas gauge does.

 

I refill when my trip mileage is equal to MPG x 10. I reset Trip A every time I refill. Usually my fills are 10.3-10.5 gallons so the MPG computer is slightly off.

By the time I refill the computer is telling me I have no range left and the lower bar has been blinking for some time.

Today I refilled at 520 miles.

 

Maybe this has already been asked and answered before (so sorry if this is a repeat)....is the following correct?

(1) the last bar on the gas guage begins to flash when there are approximately 3 gallons remaining?

(2) As you continue to drive and use up another gallon of gas (ie only about 2 gallons remaining), does the single bar continue to flash, or does it disappear, and some other low fuel warning light come on?

Thanks

 

(1) only <2 gallons (6.5 litres) remaining, the other missing gallon is at the top, that's when you "top" it up it doesn't really fill right up to the physical top of the 11.9 gallon tank (to avoid gas spillage), and that's why the average tank takes about 9.something gallons only.

(2) yes it keeps flashing, but some members here say it'll let you drive another 100 miles before it's absolutely dry.

I'd go find a gas stations and fill it up as soon as the gauge is flashing. Why risk any possible harm to the fuel pump just to go after some silly "600mi+ tank range" record number? Actual fuel economy is the real measurement. Who cares if I have to fill it up earlier? (like, by a day!)

 

Not concerned about some "tank range record".

This has more to do with - do I fill up before my 40 mile comute home tonight...or can I wait until I get home to fill up at my local gas station that has cheap prices?

The last bar is flashing, and when I check the "miles until empty" readout, it says I have 15 miles until empty. I assume that after that reaches "0 miles until empty", I still have (about) 1.6 gallons left in the tanK? Is that correct?

 

I get an average of 610 miles on a tank of gas. I fill up shortly after it shows I have zero miles left. Most of the time I put about 10.5 gallons in.

I use ‘Trip A’ to track MPG per tank and ‘Trip B’ per trip. Here is a picture of my last 4 fill ups and I have drove 328 miles since my last fill up.



Here is a picture of my current MPG per this tank of gas. I have drove 328 miles with an average of 59.6 MPGs.