Gas Gauge accuracy

^ there is something else wrong as well - I now have an engine warning light, which is all I want in a 5-week old car. Buyer's remorse kicks in ..

 

Just take it in, probably just a sensor is bad, it happens.

 

I've found the gas gauge pretty accurate (I typically drive an additional 20km after the low fuel warning, and fill up 32-33L (the tank is 35L, which is absolutely tiny.. I really wish the tank was bigger..)), but I do have a number of major complaints about it though:
1) User Interface: although they haven't changed the visual elements much since the 1st gen Prius, in the C, the display elements are much more cramped together vs. keeping the elements visually and spatially separated (eg, on the 1st gen Prius, the speedometer reading was on the left and totally independent and uncluttered; the fuel gauge was on the far right, next to the transmission gear indicator); additionally on the C, because of its location right next to the attention-grabbing color info display, I find that I simply do not notice the fuel level graph- I'm more likely to glance at the color display and see my MPG vs. the fuel level indicator, which because it is grouped with the speedometer display, simply blends into the "border art" around the speed because it's all the same color. Even when you're low on fuel (see next point), the gauge shows a flashing bottom bar, but it's at the very bottom and a very small visual element that simply does not stand out and unless you think about it when looking, it's basically invisible..
2) When you run low on fuel, in addition to the invisible flashing bottom bar, you get a very quiet beep and a low fuel warning message on the info display once and once only.. If the cabin was noisy or you had the radio turned up and you didn't see the warning pop up on the info display, too bad, that message and the warning never comes back to warn you..

For many people, they fill up when the gauge gets to a 1/4 tank, but given the small tank in the PriusC, that means you're filling up a lot more often, and sometimes, it's simply not convenient to have to interrupt my trip to find a gas station.. Part of the appeal of a hybrid for me is not just using less gas, but also the convenience factor of having to fill up less often; by putting in such a small tank, Toyota has negated the convenience factor..

On my 1st generation Prius, the dash/info display was separate and uncluttered, meaning you'd actually notice the fuel level vs. having it blend into the border art around the speeed. Now unfortunately, the low fuel beep was similarly too quiet, but it at least came back every time you started the car (when things are generally quieter and you're more likely to see/hear the warning) until you filled up again, and the tank was also bigger, at 45L, and my reserve capacity when the low fuel indicator came on was about 10L (I put in about 35L every time), so basically I was filling up about the same time, but I had a lot of confidence that on the highway, I could make it to the next town or finish whatever my errand was without worrying about rushing to find a gas station because I might run out of fuel..

I love the vehicle otherwise, but the fuel gauge display and small tank size are a major detractor for me.. The point of having a vehicle is to drive it, and not have to worry about filling up or running out of gas- most other vehicles have actually increased the size of their tanks- 55-65L tanks in compact and midsize cars are not unusual these days, and while it hits the pocketbook a lot harder when you want to fill it up, you also don't have to fill nearly as often..

 

I don't mind the small tank in C. Size doesn't matter when I can drive 450 total miles out of a single tank. Not many cars do better.
I'm still validating the computer mileage with a fresh full second tank in use... I hope I'm really getting 55 MPG average! I just got the car last weekend and have total of 600 miles now... I don't think the dealer fully filled up the first tank. So, my computation was off by 6 MPG vs. display.

 

I remember in another thread people said that Prius c gas tank doesn't have a bladder.

The fuel gauge is inaccurate indeed; the first 2 or 3 bars disappear much slower than the following bars.

 

40,000 miles and fuel gauge works fine, top half of the gauge will last longer then the lower half. It's the way it is, not a defect. You sure don't seem happy with your new car. What did you drive prior to the C?

 

I'm so relieved it's not defective. I would just like it like to be somewhat accurate, as one might expect of an instrument.

Cars

 

Which I think has been typical of every gas gauge made in the last 50 years or so.
My motorcycle does it; so did my last two lawn mowers.

 

You are not alone, very many of us would also like to have an accurate instrument there.

But many consumers are not automotive engineers, and don't fully understand the many factors that cause wildly variable fuel consumption and make accurate machine forecasts of the road ahead impossible. Because of that, if given an accurate reading, a certain portion of them who try to cut it close will fail. That leads to angry customer feedback about "... but the car said it had enough gas!".

To cut down on the millions of potential complaints, the car makers must manage customer expectations. Thus, the top of the gas gauge is not at the true top of the tank, and the bottom of the gauge is not at the bottom of the tank, and there is enough safety margin built in that nobody can legitimately claim "but there was no warning!" that they would run out of fuel.

This management of customer expectations extends far beyond the fuel gauge. E.g., after getting an OBDII scanner, I learned that the rock-solid temperature control of a past car was not real, but just an artifact of a non-linear gauge. The span from 150F to 210F was collapsed to a single point.

 

^ a lot of good info on customer expectations, but I still think the fuel gauge on my 'c' is plain inaccurate

I have a very basic and cheap 2007 Accent, and the fuel gauge is like this: give or take 90 mi - down to 3/4, 180 mi - down to 1/2, 270 mi - 1/4, after which the "customer expectation" trick kicks in .. at about 310 miles the low fuel warning sign lights up, which means I have about 50 miles left.

 

Does the cruising range in the drive information screen NOT reset unless you fill the gas tank ALL the way up?

The other day I just put in like a few gallons and the bars went to to 4 but cruising range never reset and still showed the previous range of 1.