Estimated fuel range.

i don't know about the c, but mine has always reset. however, the least amount of gas i've ever put in is probably 5-6 gallons. you should always shut it off when fueling for safety reasons.

 

I know that the Gen 2 would not register less than 3 gallons as adding gas. I have no idea what the minimum is on the c. I would let it get to 1/4 tank and try a fillup.

 

Don't put too much stock in the miles remaining display. It is just a crude estimate, unconnected to the actual (possibly highly variable) conditions ahead, and has a healthy safety margin built in if the miles ahead are similar to the miles behind. Just ignore it and fill up at any time you wish.

 

My range remaining was off too when I first got the car (5 weeks ago), it gets more accurate as the tank gets lower and with more fill ups...might need a certain amount of data for its estimates. At 50+MPG you should get around 400 miles to the tank and be putting 7 gallons and some change in when you fill up.

 

I have found the cruising range way off. Usually I have 2-3 gallons left and it reads 0. I always fill it up to a full tank with the car turned off. The pips on the fuel bar are fairly accurate. It seems that the top pip is actually 1.5 gallons and the bottom pip is actually 2 gallons. All the in between are 1 gallon each... or maybe 0.9 gallons to make up for the extra at top and bottom.

 

Your dealer "fills" up your tank... the halfway mark stays at halfway from "true" half a tank and sticks there for almost 80 miles (in my experience). The only cases where I ever trust the miles remaining gauge are when I personally fill it to full, the moment it hits half (not later on) and the minute it hits 0 (at this point I know that I have more than a gallon left and to start looking for a station, but that is your option and I don't recommend pushing it if you don't feel comfortable... just know you have miles after 0).

 

You can get an instant MPG and it will actually record the trip from ignition to shut down or as you mentioned trip a and b.

 

Well, I apologize before hand for somewhat muddying the waters here, because I'm talking about my Prius 2, not a Prius c.

But I just did my first fill up. When I got the car brand new, a little over 2 weeks ago, the dealership had filled the tank, and the Miles to Empty or cruising range estimate showed 600 miles. Okay, so I drove it until the last pip starting flashing, then pretty quickly refilled. At the time I refilled the miles to empty display showed 29 miles remaining.

The Prius filled with over 9 gallons. I kept the receipt and marked my mileage down so I can more carefully track it this tank.

But what I noticed is immediately after filling, when I turned the vehicle on, the miles to empty or cruising range reset, but NOT to 600 miles, it reset to 579.

It doesn't really matter to me, I'm NOT going to trust the cruising range or miles to empty, and with the extended cruising range of The Prius, I think I'm probably always going to fill up with 2 or 1 SOLID pips remaining, regardless of what the cruising range says I have left. With the pip flashing, the fill was just under 10 gallons, which would suggest I had about 2 gallons remaining....which could be quite a long distance left to drive. But to me? Why push it, and why not enjoy driving further than a normal car, and filling up with less gas?

But for the life of me, I can't figure out what computerized "logic" is being applied to the cruising range estimate. If the gas station pump is correct (no reason to believe it is not)...then with my Prius's 11.9 gallon capacity tank, I had a good 2 gallons left, even with the pip flashing. So if I had driven even just 1 more gallons worth of the two remaining I would of easily put the cruising range or miles to empty into the negative....

I've read enough "horror" stories from owners running out of gas, and I have no desire to put My Prius nor myself through anything like that. So I don't really care. I realize the miles to empty or cruising range estimate, is just that, an estimate, but even with a computerized "estimate" there has to be some logic being applied. I can't figure it out.

As far as I can tell....it's just a distracting number from the actual gas gauge, that you really can't trust for anything. It can make you feel good when you first fill up and see how many 100's of miles it says you can go...but is it really anything more than a feel good, fill up placebo?

 

It's relatively close... but it will show the same mileage for a few miles. I had 9 miles left for about 15 miles.