Auto Reset of Avg Fuel Consumption Readout

<div class='quotetop'>QUOTE(ekpolk @ Aug 30 2006, 10:48 AM) [snapback]311608[/snapback]</div>

As far as I know there is no way to avoid the automatic reset.

On your next tank, notice how it behaves. In the first few miles the MPG will be all over the place. I usually fill up at a station close to work. Running EV most of the way to park, the readout will be 99.9. But leaving it will quickly drop to the 40's or even the 30's by the time I exit the campus. After a couple hundred miles a mile or so of EV will up the mileage by only 0.1 or 0.2 MPG.

If it did not reset and you get a thousand miles or more, it will rarely change. Ten thousand and you will think it is broken.

The best option would be to use a PC or PDA program to track it. (I use TealAuto on a Palm, but there are a number of other options.) This way you can track how the mileage changes with seasons and experience. This will also provide a total mileage reading.

 

it resets when you add 3 gallons. so you could add 2 gallons at a time, but that sounds like a pain.

 

<div class='quotetop'>QUOTE(jfschultz @ Aug 30 2006, 12:28 PM) [snapback]311662[/snapback]</div>

Uh oh, I feel a TonyPSchaefer post coming on...

(he has a very good spreadsheet showing average MPG and average temperatures, check out his profile, there's a link there somewhere).

The first time it reset on me, I was a little upset, because I thought there was a way to keep track of lifetime MPG. But that has to be done on old-fashioned paper, or PDA/spreadsheet... but not on the MFD.

 

<div class='quotetop'>QUOTE(nerfer @ Aug 30 2006, 02:40 PM) [snapback]311695[/snapback]</div>

The early 2006 models do not reset the MPG number, only the miles on the tank (even though the manual says they both reset). Does your 2006 reset both? If the MPG display does not jump around for the first few miles after getting gas, then it is not resetting. I had not heard of anyone with a 2006 that has the old 2004/2005 behavior.

I always hit the reset button after getting gas because I want both miles and MPG to reset. On a long trip, I might leave it alone to get MPG for the entire trip.

- Tom

 

<div class='quotetop'>QUOTE(ekpolk @ Aug 30 2006, 11:48 AM) [snapback]311608[/snapback]</div>

The problem is that it would be too stable. I don't believe it would do what you are hoping for.

Lets say your MPG calculation never reset. If you achieve 50 MPG for gallon for 5000 miles,then you MPG calculation would read 50 MPG. All good, right? But then lets say you got 10 MPG for the next 300 miles. At that point, your MPG calculation would read 47.7 MPG. Is that what you would want it to do?

After several thousand miles, the collective weight of all of the previous miles would make it so stable that it wouldn't be very useful.

 

<div class='quotetop'>QUOTE(Marlin @ Aug 30 2006, 02:07 PM) [snapback]311708[/snapback]</div>

Eh... Y'know, I was just going to leave mine without resetting, so I could have a lifetime average without having to calculate it myself, but that's a really good point.

 

<div class='quotetop'>QUOTE(ekpolk @ Aug 30 2006, 05:39 PM) [snapback]311778[/snapback]</div>

I have owned both an '05 and now an '06 Prius. The '05 Prius would automatically reset the MPG upon fillup, while the '06 does not--only the mileage driven since last fillup automatically resets.

Hope this helps!

 

<div class='quotetop'>QUOTE(dvdirv @ Sep 1 2006, 11:44 AM) [snapback]312759[/snapback]</div>

unless of course you do what I did....The MFD had some finger prints on it...sooooo while the car was on I decide to gently wipe the mfd....bingo reset button pushed...

Moral of the story...shut the car off before cleaning MFD!

 

<div class='quotetop'>QUOTE(ajs @ Sep 8 2006, 11:52 AM) [snapback]316491[/snapback]</div>

Or shut off the MFD before cleaning it, if the car is on

 

I've put 4 tanks of gas in my '06. On the first one the miles reset. Since then, nothing has ever reset automatically. Perplexing.

 

You might try turning the car off, then hitting Power twice with your foot off the brake to get into the 2nd ACC mode (forget what the term is for 2nd Power on mode). I would do that while filling up if I had passengers so they could listen to music while I was out or play with the navigation, etc. I noticed that this tends to interfere with the car recognizing the fillup has occurred which would trigger the reset... neither the miles nor the MPG got reset at my last fillup when I did this. I have an 06, just got it a little over a month ago.

Being pretty new to the car, I actually wanted measurements taken per tank so I can tell if I'm improving my driving and MPG, so I reset it before I pulled away. I suppose later on down the road, this little trick might come in handy if I want to take measurements that span a few tanks like a road trip (a really long one) or the length of a summer or winter season or something.

 

So, this reset occurs after the vehicle is stationary and the fuel
tank content rises by some delta. It would be an interesting
experiment to see if the reset occurs when fuel is added WHILE
MOVING, or at least registering some nonzero VSS value. This could
be done electronically, or by physically lifting one front wheel
off the ground and letting it slowly spin in "creep" while pumping
in gas. The electronic-only approach would probably be less likely
to weird out gas-station attendants, though.
.
Hmm. I've already got easy access to the wheel speed sensors, and
there's a tone generator kicking around the shop somewhere...
.
_H*

 

I really prefer te tank-to-tank method of attacking FE. It's nice to start fresh and see how high your numbers can get in a short period. And it gives you a target you can actually hit, and have some impact on.

Ultimately a running total on paper (or spreadsheet software) is a really good idea regardless of what the MFD says. You can track more than just miles and FE that way; I have dollars per tank, price of gas, days between fills, avg temperature, and a bunch of different comparisons on my spreadsheet, and it's a great way to see how things change and why.

It's a good idea to do the same for your non-hybrid cars (ok, maybe not EV cars) as well, if you're unlucky enough to have them. Not just for comparison to your Prius, but also because you can make small differences in other cars just like you can in the Prius. It all makes a difference.

 

My '01 never reset itself and I liked that. Then if I took a trip that was longer than one tank of gas I could get the mileage for the trip. My '04 did the same thing until the first computer recall and since then it resets at each fillup. You usually have to drive about an 8th of a mile before the reset. I am with the OP. I think it should not reset unless the driver wants it too. I am all for having as many driver preferences controllable as possible. It sounds like to get what I want would take a computer downgrade back to the way it originally was!

 

<div class='quotetop'>QUOTE(hobbit @ Sep 9 2006, 06:28 AM) [snapback]316919[/snapback]</div>

I used to do this in a B-52 behind a KC-135. I can verify that the fuel guages do reset then. And you're right, it is interesting, especially during bad weather at night.

It'd be fun to hook up a Prius behind a Hummer tanker dragging a hose in the breeze (over a bumpy road.) Trouble is, he'd probably run out of gas before we completed the refueling.

"Breakaway, breakaway, breakaway!" (For folks who remember those days.)

 

I just don't understand why Toyota didn't put a "lifetime MPG" feature on the MFD.

I know the Honda Insight has it and I feel its a pretty useful number to have as a reference.

 

In my 07 the miles reset but the MPG does not. Might be because I put it in park instead of off since the engine isn't running anyway...
I know I know... please don't call Homeland Security on me..

I like the classic better in this regard. As long as you didn't press reset, nothing reset at fillup.