We have an '08 MMH with Nav and the Energy Flow screen. On that screen, I can display my average MPG and I reset it every time I get in the car (a habit from my HCH). However, I would also like to know what the computer thinks is my average per tank (Trip A). Is there a trip related average mpg function buried somewhere that I haven't found yet? If not, are there any easy ways to track tank mpg other than by recording each average datapoint before I reset?

 

Once you are at 200 or so miles into a tank, the (MTE + Trip A)/13.7 gives a pretty good estimate to actual tank MPG on my 2005 FWD FEH. Assuming, of course, that you reset Trip A when filling the tank.

 

MTE=Miles to Empty? And 13.7=tank size? Thanks!

 

Yup. Right now, I have MTE=23, Trip=520.6, AVERAGE ECON=40.5, AVE.=41.3 (Nav display)

So, the MTE says MPG=(520.6+23)/13.7=39.7 MPG, which means the instrument cluster is 2% high, the nav 4% high. My scangauge was disconnected during this tank, so it doesn't have an accurate reading.

All this assumes you do not overfill the tank (bad for evap emissions) and that you reset the trip odometer at fill up. I am going to fill up now and will post what the hand calculations are, but I bet it is closer to 39.7 than 40.5...

 

Cool--thanks! It looks like I'll need to buy a pocket calculator to keep in the center console .

 

And the results are: 530.3 miles on 13.45 gallons, for 39.4 MPG.

When stopped for fillup, MTE was 13, so (13+530.3)/13.7=39.7, pretty close, certainly within the fuel filling error.

Even though I didn't break through the 40MPG barrier, my MTE after fillup was 610, first time over 600 for me!