How to average MFD MPG's

<div class='quotetop'>QUOTE(morpheusx @ Aug 26 2007, 09:00 AM) [snapback]502139[/snapback]</div>

I concur
Only on a Prius site would you see such a thing.
I'm a little disappointed there is no coloured pie chart with some pieces of the pie expanded out of the circle.
How about one of them nifty graphs where it had bars above and below the centre line?

You might notice I have no idea what I'm on about.
Nerds.

It's good to see that correlation between ambient air temperature and fuel use.
I'd love to see a graph showing the affect of the average speed of a journey on economy and another journey distance.

 

<div class='quotetop'>QUOTE(patsparks @ Aug 25 2007, 07:49 PM) [snapback]502142[/snapback]</div>

Hey, no problem. I'm leaving until tomorrow, but I'll whip some of those up for you when I get back. [attachmentid=10906]

 

And while you all are having fun being so precise, remember that:

1. The odometer is intentionally incorrect by a percent or two

2. As the tires wear, it is more incorrect

3. The gallons pumped are a function of the temperature of the gasoline in the station tank and that is not
controlled

4. When gas pumps are checked for accuracy it is amaziing how much they vary even with state controlled
standards in force.

5 If you have changed tire sizes the odometer is likely even more off.

Even at the best, gasoline consumption is an ESTIMATE.

That said, our cars get the best gas mileage compared to all the rest!

 

Just for fun I assembled the records for my past 3 cars. My MPG has had a close correlation to gas prices though I purchased a Prius a bit before the recent large spike.

 

<div class='quotetop'>QUOTE(GeoDosch @ Aug 25 2007, 09:54 AM) [snapback]501948[/snapback]</div>

<div class='quotetop'>QUOTE(GeoDosch @ Aug 25 2007, 08:00 PM) [snapback]502147[/snapback]</div>

Could you e-mail a copy of your Excel spreadsheets? Send to [email protected]. Thanks.

Blue Hoosier

 

<div class='quotetop'>QUOTE(Blue Hoosier @ Sep 8 2007, 06:51 PM) [snapback]509219[/snapback]</div>

On its way

 

<div class='quotetop'>QUOTE(Blue Hoosier @ Sep 8 2007, 06:51 PM) [snapback]509219[/snapback]</div>

On its way

 

Maybe I'm just not understanding the way the mfd works, but if you just never hit the reset button won't you accumulate a running average on the mfd?

 

Maybe I'm just not understanding the way the mfd works, but if you just never hit the reset button won't you accumulate a running average on the mfd?

 

<div class='quotetop'>QUOTE(emailcurt @ Sep 13 2007, 02:25 PM) [snapback]512050[/snapback]</div>

Yes you would. Right up to that time when you accidentally bump the reset button on the touchscreen while wiping a smudge, then poof your information is gone.

There are a lot of reasons for tracking your MPG in a spreadsheet or online frmo tank to tank, but if all you care about is lifetime MPG and you never accidentally press teh reset button, then your plan will work just fine.

 

<div class='quotetop'>QUOTE(emailcurt @ Sep 13 2007, 02:25 PM) [snapback]512050[/snapback]</div>

Yes you would. Right up to that time when you accidentally bump the reset button on the touchscreen while wiping a smudge, then poof your information is gone.

There are a lot of reasons for tracking your MPG in a spreadsheet or online frmo tank to tank, but if all you care about is lifetime MPG and you never accidentally press teh reset button, then your plan will work just fine.

 

<div class='quotetop'>QUOTE(emailcurt @ Sep 13 2007, 03:25 PM) [snapback]512050[/snapback]</div>

Your statement is correct, so there's probably nothing you're misunderstanding about that aspect of the MFD. But if you're wondering why go through any additional trouble with tracking mileage, for me there are several reasons. To start with, I've been tracking my mileage and usage long before I owned a car that had a mileage computer. Tracking it on a spreadsheet lets me see the trend, so if I start to see my MPG drop, I'll know there's likely a maintenance issue. I also get a lot of other info, such as how much I'm driving, what it's costing, etc. And I also like that I'm checking actual driving distance vs. how much fuel I've used (odo and pump inaccuracies notwithstanding.) The MFD is a great guide, but without comparing it to actual numbers, I'd have no idea how accurate it is. (from my limited comparison, it seems to be slightly optimistic, though pretty close.) And lastly, as was previously pointed out, as a programmer I have my nerdish tendencies.

 

<div class='quotetop'>QUOTE(emailcurt @ Sep 13 2007, 03:25 PM) [snapback]512050[/snapback]</div>

Your statement is correct, so there's probably nothing you're misunderstanding about that aspect of the MFD. But if you're wondering why go through any additional trouble with tracking mileage, for me there are several reasons. To start with, I've been tracking my mileage and usage long before I owned a car that had a mileage computer. Tracking it on a spreadsheet lets me see the trend, so if I start to see my MPG drop, I'll know there's likely a maintenance issue. I also get a lot of other info, such as how much I'm driving, what it's costing, etc. And I also like that I'm checking actual driving distance vs. how much fuel I've used (odo and pump inaccuracies notwithstanding.) The MFD is a great guide, but without comparing it to actual numbers, I'd have no idea how accurate it is. (from my limited comparison, it seems to be slightly optimistic, though pretty close.) And lastly, as was previously pointed out, as a programmer I have my nerdish tendencies.

 

Maybe our Prius are messed up but when we fill up both our MPG and miles reset on the MFD after 0.4 miles driven. Did you guys have to set something to make it keep a running average?

 

<div class='quotetop'>QUOTE(Tadashi @ Sep 13 2007, 10:23 PM) [snapback]512277[/snapback]</div>

When you refill, the miles on the MFD automatically resets, but the MPG does not. (Don't ask me to explain that, as it seems counter-intuitive to me, and I can't think of a benefit to having it that way.)

 

Are you sure? Both my settings go to 0.0 once I get 0.4 mi from the pump (checked it with my odom display). If I am driving all elec I can get 99.9 after the first mile.

Normally, it would take driving around quite a bit to affect my avg MPG. The first part of the tank it is fluctuating quite a bit (jumps +/- 30-40 MPG). As I near the end of the tank my MPG rarely budges +/- 0.1 MPG unless i gun it for a distance.

 

<div class='quotetop'>QUOTE(Tadashi @ Sep 14 2007, 08:26 PM) [snapback]512807[/snapback]</div>

The 2007 only resets the miles driven to zero on MDF. I think in some posts I read that the 2005 and earlier models did reset both numbers. Since you have an 05 model it seems to confirm my memory.

 

OK - I'll admit to being an EXCEL nerd. I record my MFD MPGs for each tank (resetting the MFD with each tank), as well as tracking the miles and gallons for each fillup and calculating a 'spot' MPG to compare with my tank's MFD MPG. I also calculate 2-tank, 3-tank, 4-tank, 5-tank and cumlative weighted averages for the calculated MPG and the MFD MPG. But I've done the same with the last three cars I've owned (including sometimes plotting line graphs of the various results). Yes, I need to get a life.

But it tends to keep me sharp on my EXCEL skills for the frequent times I need those skills at work.

 

<div class='quotetop'>QUOTE(Prius 07 @ Sep 14 2007, 08:12 PM) [snapback]512832[/snapback]</div>

That's certainly what happens on our '05.

 

Ah so that is it. I wish we could plug something into the display that allows us to customize the display. It would be sweet if I could get my excel workbook to auto fill data and email itself to me after each fill up. Then again what would I do with all the time that would free up. I definitely need to get a life.

Speaking of which I made a generic Single Prius spreadsheet from based on my Dual Prius sheet. Link should be in my signature below. hehehe it did get me out of laundry duty. Told the wife I was working on something for work.