<div class='quotetop'>QUOTE(dnoh @ Apr 24 2007, 12:10 PM) [snapback]429083[/snapback]</div> dnoh, I use the same method but I reset the MFD. Occasionally I'll have a variance of 20% on a tank comparing my calculation to the MFD. So far the MFD has always been higher. Usually the calculation is within 2%. Over 11,000+ miles the mpg is rather constant. Check out what others are getting on greenhybrid.com. Yep, the guess gauge is inaccurate and an annoyance but guess what? So is the analog gauge in my Intrigue. The difference is perception. I perceived that a digital gauge should be more accurate than an analog one. There is also less to complain about compared to a Brand "O" car so the gauge floats to the top of the list. Your next emotion may be that you are too anxious for the next fill-up but will have to wait 2 weeks.
Too much talk about the bladder in this thread. The bladder doesn't make gasoline disappear so it will have negligible effect on your average mpg over several tanks. Think about it this way. Assume the bladder takes up 1 gallon volume. Your first tank may be 1 gallon off if it is fully "open." Your next tank will be 0.5 gallon off and so on. After 10/11 tanks or 100 gallons, you'll still be 1 gallon off or 1% off. You're not going to be able to calculate better than 1%. To answer your original question, the dealer didn't fill full. The dealer filled to 10 bars so it looks full. You can roughly count the number of bars missing to see how many gallons you'll fill plus or minus.... You guessed it 1 gallon. You can expect the MFD to be 2 mpg optimistic. If you're seeing 47 mpg, you're actually getting 45.
I love this analogy. Now watch, someone will try to put a brick in their gas tank to squeeze out extra mileage............. (LoL)
Is there a way to display the amount of gallon of gas remaining in numbers on the prius screen? I can estimate based on the total gallon available and the percentage shown on the screen, but I was wondering if there's a way to see the exact number of gallon of gas left while driving.
Unfortunately not. There is a reason that the gage is often referred to as 'Guess Gage' on this site.
It can be displayed using a ScanGuage but it is not very helpful because it is not dampened, meaning that it fluctuates quite a bit such as when you go around a curve.
On the Prius screen? No. But various OBDII-port engine monitors should be able to take the internal fuel gauge reading and display a number. E.g. a 'FLV' X-gauge can be programmed into a ScanGauge-II and display a gallon number, at least for Gen3. Many of the more modern OBDII-port products should do the same. The ScanGauge version does not filter out the slosh, so swings wildly. And its zero point does not match the zero point of the tank. I don't know how meaningful a Gen2 version might be with that problematic fuel tank bladder.
No, that's why everyone on this forum calls it a "guess gauge". There IS no exact. You shouldn't try to estimate the GALLONS available, but instead consider it the "percentage of usable capacity". The amount that is actually in the bladder on any given fillup will be different on any given day depending on temperature, flow rate of the gas pump, solar activity, etc. Then the cluster module adds a "kentucky windage" adjustment for temperature and tilt to muck up the reading from the fuel tank level sensor some more and spits out a number of pips on the dash. The only data that you will find in the engine computer for fuel level is either "empty" or "not empty" Forget about what you think the range SHOULD be, because the guess gauge don't care and eventually you'll get it wrong and run out of gas. The experience of most on this forum is to just fill it when you get to 1 pip.
Ah, the Gen3 with its nice, normal gas tank. IDK if any aftermarket apps or scanners have any access to fuel level data on a Gen2 or not. I was working on a 2007 this week with a gauge problem and couldn't find anything of use in Techstream. Toyota apparently didn't bother to design the CM to communicate with a scanner even though it's on the data network. The ECM data shows either "empty" or "not empty".
My dad's technique with our 58 Vdub: 1. Take gas cap off. 2. Insert and withdraw stick, see how much was wet.
We have the brand new RAV4H and it has a similar fill-up problem to older Gen2 Prius, not being able to fill up the tank, RAV4H advertised for 560-580 mile range, but you are lucky to see more than about 490 mile remaining after a fill up. Toyota has concluded that a subtle shape change in the RAV4H gas tank shape causes this fill-up issue. Apparently we are going to get new gas tanks for our Rav4H's pending Toyota decision what to do about it. If a subtle change in the RAv4H fixed-shape gas tank accounts for this fill-up shortfall, then obviously older Gen2P with its shape-shifter gaso tank might explain the fill-up variability as the car ages. we were lucky to get 7 gal fill-up in our older Gen2.