Three Issues : Quirks or Problems?

1. It's not designed to be totally accurate.

2. It's normal for CC to fluctuate 1-2 mph and this has been evident in every cars I've owned. Don't mess with the control.

3. Getting more than 400 miles on a tank really depends on the route you're taking, the duration of your trips and weather condition. Don't expect 50 mpg if your commute is 3.5 miles in length or it's freezing cold.

 

1. The 2010 Gen III Prius does not have a bladder. The earlier Gen II's did. The fuel gauge is no more accurate or inaccurate than any other car I have had. It still uses the same analog float switch as other cars but converts it to digital for display.

2. No problem with my cruise control. It may drop or rise +/- 1 mph when going up and down hills but that is it. Mine also drops or raises 1 mph when bumped up or down. A lot of this depends on where you are between mph when you set the cruise. If I set mine on the high or low side of a mph, it might return 1 mph high or low. If I reset the cruise right at the correct mph, it tends to hold that mph better.

3. I average 48 mph and average 400 miles between tanks. I also refill at 1/4 tank (2 pips). The Prius keeps about 2 gallons in reserve even when you get down to 1 pip and it starts flashing. It is not good to run out of gas with the Prius. The miles you get between refills depends entirely on your average mpg.

 

If you are up in the 70-75 mph range, don't expect more than 45 mpg. Also, please fill out the questionnaire in the Fuel Economy sub-forum and post your results... perhaps we can help squeeze a few more mpgs.

 

Greetings and Welcome!!! :welcome:

I loved the answer you got from Toyota btw....classic!!!
If it's 'fairly' inaccurate, then it's also 'fairly' accurate. If your fuel gauge is like mine, it's somewhat accurate, but not linear. Remember...when the last bar starts flashing, you have the better part of two gallons left. If you spend your days with a calculator trying to assign a gallon value for each 'pip'---you need a hobby (sorry! )
The purpose for the gauge is to provide a visual approximation of the fuel in your tank.

My GMC stays within 1-mph when the CC is engaged....BUT it has 315 BHP, and 335 ft-lbs of torque. The Prius is built for different things, so I think I would accept a 1-2 mph variance in the vehicle speed when the CC is engaged, which is what I see in mine.
Caveat: I live in an area that's mostly flat.

I'm sorry, but that's a problem between the seat and the accelerator petal. Use Eco, check your tire pressures (consider clubbing up to 42/40) and limit your HVAC use. Also don't pre-warm your vehicle. Other 'fuely' tips abound in the forum.
Read up! It'll give you something to do with the time that you spent on determining the gallon-per-pip value for your fuel gauge.
(oops! ...sorry again!! )

I'm sorry, but the dealer might be right....and you might be picking nits. If you like your G3, just relax and enjoy it.
I'm not a Prius cheerleader by anybody's definition!!! There are items in the Prius ownership experience that I believe warrant further development, and you'll read about them in their full glory in this forum however (comma!) the G3 in general is a well engineered, well executed car that just happens to get phenomenal fuel economy (when properly driven) and it seems to be somewhat reliable. Your 'problems' might not be problems at all.

Good Luck!
Let us know if the mileage improves!!!

 

So Toyota Engineers are brainstorming about The Fuel Gauge.

We can make it accurate?....no...too easy....wouldn't want people to know exactly how much fuel they have left, have used or can use....take the fun out of life...

We can make it inaccurate?...no...if word got out we did that? We'd have another recall...

Let's make it....Capricious....

 

The Gen III does not have a bladder, as has already been pointed out. Your dealer is out of touch with the new models.

It has a conventional float sensor. These slosh around with the fuel going up and down hills. So, in true Japanese anal-retentive fashion, they included an inclinometer. The system knows if it's going up a hill (or down) and corrects the sensor signal. This device is a little accelerometer and they need calibration. If it's off, the correction can make the display show low when there's still plenty of gas in the tank. I know it can be calibrated with a Techctream, just don't ask me how.

The cruise control doesn't know you're going up a hill until the speed slows down (it doesn't use that fuel-gauge inclinometer). So the car has to slow a little bit in order for the cruise to know it has to apply more gas. How much is related to the tuning of the cruise control math. Yes, the Prius cruise control is tuned very slowly, and speed does vary more than other cars.

You have 11.9 gallons, but probably should fill up with 1.9 left. Multiply the Avg Cons by 10 and fill up then...unless you can get them to fix the fuel gauge.

 

when you say you 'can't go more than 400 miles', do you mean you run out of gas? or the display says you have 0 miles left?

 

I have never averaged more than 45mpg, it's all how you drive

 

so you can go 450 to 500 miles on a tank?

 

If you drive in ECO, the CC lets the mileage vary a bit to try to get a slightly better gas mileage. And even if you don't, a small engine by definition will cause the speed to vary with terrain when using CC. Finally, realize that if you push the CC stalk to resume and hold it a bit too long, you will be resetting the speed anyway. Read the manual and you'll probably find that it is operator error.

And we hope you post again in reply to our messages so that we don't accuse you of being a troll working for GM.

 

One of the biggest drawbacks of the fuel gauge is that it only shows your tank level in about 8 effective steps. If you are use to an old fashioned analog gauge, then you "feel" that it tracked steadily (if not linearly) vs. the jagged jumps of the Prius gauge.

You need to let the Prius work on you for a couple of months. Soon you driving style will change from the standard American style of liftoff and landing to steady driving in spite of the jackrabbits around you.

 

While all this has been addressed, this question is too vague:

What is your definition of 'a tank'? Actually out of fuel? DTE=0? last pip flashing? 2 or 3 pips left? Different people use different reference points, so we can't really help until you are more specific.

And you much gas are you putting in when refueling, at the above point?

As for your fuel gauge inaccuracy point, mine is quite normal for the auto industry-- better than the Subaru I still have, same as the Honda and Ford before that. Only a much earlier Ford had a gauge with appreciably less error. Unfortunately, its smaller error was in the wrong direction, as I discovered when it ran dry with the needle still above E.

 

That's not quite right. The low fuel light starts flashing when there are 19 or 20 miles left according to the DTE (i.e., the low fuel light starts flashing way before the DTE reaches 0 miles).

 

HEY now, careful, you know who is watching.

 

Evpv where u at fool

 

Regarding #1: I wouldn't mind if the car's fuel estimation was randomly inaccurate, but in my limitted experience it is consistantly and precisely inaacurate, in Toyota's favour...

Regarding #2 and #3: they may be linked: cruise control is not going to help with mileage, particularly where you're encountering grades. You will do better letting your speed fall off on upgrades, and recouping on down grade. As long as you don't start collecting irate leadfoots.

 

1, I've never had a car where the fuel gauge was acurate. The Prius is no different.

2, All cars I've ever driven with CC have all varied when going up or down hills.

3, I have managed to get more than 400 miles to a tank on many occasions.

And yes I do think you are being too picky