Newbie wants to know....

No. Gauge is nonlinear and you will go nuts if you try to use it to calculate gas consumption. Use the gas gauge for one purpose only: should I stop for gas now or can it wait? You will be much happier.

 

Well, maybe one other purpose. You'll know with 6 pips you had less gas than with 7.

Seriously, it gives you a glimpse of the relative fuel level, but it is imprecise and, like HOVZOOM says, nonlinear. All fuel gauges are nonlinear for that matter, but that aspect of the Prius gauge may be a little more exaggerated because of its flexible fuel bladder. For example, I've gone as many as 250 miles on the first pip in hot weather, and as few as 60-70 in mid-winter.

Like he says, use it to let you know when you need fuel. It is most trustworthy when the last pip starts flashing and the MFD says "Add fuel."

 

All pips showing = no worries
Two or three pips = get gas soon
One flashing pip = GET GAS NOW!!!

 

I have to say that of all the features of my Prius the gas gauge is the only one I am close to being embarrassed to mention to other people. The car is truly a technical marvel yet Toyota can't design a better gas gauge. Maybe an accurate gas gauge is a super-secret of the next generation Prius?

 

Wanting to use greater than 8 gallons per fillup in an intriguing topic.

Less than that, the gauge reads just fine. It's the desire for a further range that complicates things. I suggest justifying why more is better. Toyota hasn't agreed to that in the past... hence the "Add Fuel" triggering sooner in this model than the previous.

Protecting the battery-pack has been the paramount priority.

.

 

No big mystery -- its an engineer (or fill in the blank) thing. I just like the idea of an accurate measuring instrument. Sometimes I am OCD where measurements are concerned and there is an expectation of some degree of accuracy. Maybe a uni-directional strain gauge that measured the weight of fuel over a short period of time so acceleration and deceleration would not effect the measurement too much.

 

Like I said, intriguing.

Why then is there no concern expressed for seeing charge-level below 40% for the battery-pack?

Isn't that the same situation, not being shown something we shouldn't be depending on anyway?

.

 

I just don't understand why so many people have issues with the fuel tank/guage in these cars. I mean I can understand Jack66's problem, he is an engineer and has measurement issues but for the rest of you what is so hard about just driving the car and filling up when it hits 2-pips?

There are so many other things to worry about in life, the Prius fuel tank is not one of them. LOL

 

Because I don't look at the battery SOC display and I don't equate it to running out of something that I need to keep track of.

The gas gauge really isn't a big deal to me and I just fill up around 2-3 pips with reckless abandon or decide to get a little crazy and do something different. I don't really need to know that I have 8+ gallons in the tank. The engineer in me likes to know that the tank currently holds 6.4321 gallons even though it doesn't mean anything or change the way I drive.

Personally, I am surprised yet a bit relieved that Saminjax has not tried to relate my need to measure things accurately with a male's preoccupation with size.

 

Here you can see that even without the bladder in the fuel tank the fuel gauge is not linear.
http://priuschat.com/forums/prius-m...asy-understand-illustration-4.html#post591565

 

Not totally understanding the fuel system but it seems that a simple sensor should know if the tank is truly full. That should be all that is needed. Since the car obviously has a flow sensor it should be able to calculate the actual gallons used with pretty good accuracy. Tank capacity - gallons used should show fuel remaining.

I know, some may still be in the tank due to filling the filler tube but it should be pretty close. The point is, a reasonably accurate gage shouldn't be that hard.

Bob

 

Today my car went from 2 pips to flashing 1 in no time flat. Planned on filling at Sam's today but started to freak when the darn thing started flashing. Fortunately Sam's was @15 miles away so I passed up on the gas stations with prices 6¢+ more than Sam's prices. Was I acting unreasonable considering the flashing pip?
BTW, I followed PC posters' recommendations and fueled slowly and got more than 10 gallons before the pump clicked. I tried to fill at 3 pips on Wednesday and the pump clicked at <3 gallons and still showed 3 pips.

 

Hi Sandi,

No you did not act "unreasonable"; when the last PIP flashes you have to fill up. Based on the rest of the information you may have an issue with your gas gauge. I would monitor it for the next few tanks and try a different pump / gas station next fill-up. Given that you quickly went from 2 pips to 1 flashing one you may want to fill up when you reach 3 pips. If the problem persists perhaps your gas gauge needs to be reset. Do a search on PC for doing that.
Good luck,

 

We were on a trip yesterday and had two pips, but when I looked at the mileage and mpg I knew we had used more than 10 gallons. We pulled off at next exit with a gas station and the pump stopped at 11 gallons. I was able to sueeze a little more and stopped at 11.5 gallons! Again, two pips; never got a flashing pip or a warning.
Is this normal?

 

In my experience this is not normal. Maybe somrthing's wrong. Maybe not. Visit the dealer if it persists.

I don't think it is too much to ask for accurate gauges. However GM & Toyota seem to think so. Ditch the idiot lights and install some real gauges.