Lifetime MPG

If your grand kids are sitting behind the wheel with the car running then you have bigger issues to contend with than an erased mpg indication. If they are old enough to drive then they are old enough to instruct what not to do in your car.

 

I use Trip A for each fill-up and just let Trip B alone so it will calculate lifetime.

 

That is kind of lame. Most modern cars with an OBC track lifetime mileage. Or I should say mileage since the last time the battery was disconnected.

 

Mine was reset by a clumsy technician at the second oil change, back when it had a shorter change interval. And for some reason I mistakenly reset the wrong trip meter about once per year. But since I use it for tank mpg, not lifetime mpg, less information was lost. Results are recorded in a notebook at every refill, then lifetime mpg and other metrics are computed on a spreadsheet.

 

I just maintain an Excel spreadsheet of all my gasoline purchases that tells me that my 2004 Gen2 Prius at 220,000 miles has averaged 45.8 MPG over its life of over 8 years.

JeffD

 

Same here.

 

Is there a maximum limit on the trip meter?

 

fuelly.com

 

If you can keep track of all the gas you've bought since purchasing the car, and the odometer reading at purchase, you've got what you need. Unless the car has some sort of flash memory (not a bad idea...) it will lose overall mileage any time the battery is disconnected.

And fwiw, Toyota's track record for accurate mpg is not so good. This is apparently rectified on the Prius Plug-In and maybe on Prius C?

 

I use the attached spreadsheet. Perhaps it can help someone else out.

When you fill up fill in columns C,D,E and F. At the end of
each month if you press the "Refresh Pivot" button (around cell K22) it will keep a running summary by year and by month. :focus:

 

I use Trip A for cumulative (never resetting), Trip B reset after every fill up. I don't care about calculating per trip b/c the HIS display calculates and tells me what the trip mpg is after I turn off the ignition.

Also, I use fuelly as well, as you can see below.

 

I use a spreadsheet as well. Easy enough to compare actual MPG to displayed. I use Trip A for my daily jaunts to and from work and Trip B for my tank to tank numbers.

Actual average MPG of 47.66 from July 2009 with 37,810 miles.

 

If you set up an account and log your fillup at Fuelly | Share and Compare Your MPG can see your actuall mpg and whole lot more.

 

glad i found this thread. kinda disappointed that the gen iii prius does not keep track of overall/lifetime mpg....the older models did (although i suppose it is arguable that the stat was not very accurate anyway).

i've already made the mistake of resetting my trip a and trip b...maybe i can reset one on Jan 1 and keep track of my yearly mpg lol

 

I reset the trip (usually both) at each fillup and use Fuelly to track my lifetime.

fwiw, I've found the onboard to be about 5% optimistic over the 50k miles I've tracked.

Also, my average now, barely moves, because after so many fillups, you need a bunch of large swings to move the needle, so to speak. Basically, I could stop tracking from now to forever and not expect my average to change more then a few decimal points.

Cliff's Notes: Lifetime average is sort of meaningless imo.