Where is Cliff Notes for how to access all the MPG data?

Although a bit clunky, the Owner's Manual is your friend.

 

With the Odometer displayed, the MPG displayed beside it should be MPG the time since you last pressed "update" from the "Past Record" from the Eco > Past Record screen....


(not my Pirus, same screen).

You can cycle through the Trip A, Trip B, Odo, etc by pressing the Trip button on the steering wheel.

However, to best track fuel economy with accuracy is to use something like Fuelly or track everything by hand. I have found that the Prius reports the MPG being about 5-7% more than it actually is.

As far as cliff notes. Along with the owners manual there should also be seprate pamphlets for the Entune infotainment and some other "quick start" type things, which probably don't have this specific question addressed but assuming you have it and don't have access to Google (can find these in PDF form from Toyota too).

 

Is that your experience with Gen 5, or from past gens?

I know it’s the case with our 3rd Gen, have heard sim about Gen 4, but a few Gen 5 owners have posted here that dash display mpg is finally accurate.

 

Can't speak for the 3rd or 5th generations, but has been the case with both the 2016 Prius Two I had and my current 2018 Prius Prime +, currently at 155k. One odd thing though on both cars when they were new, the very first tank that came with the car for whatever reason was accurate on both cars. I used to keep track of the displayed fuel economy and the actual to see the discrepency but it seems to be consistently off so I don't track it anymore. Am curious about the new 5th gens but got to wear this one out first!

 

If you want all the MPG data for cheap, get a compatible OBD2 adapter for Hybrid Assistant and look at its Hybrid Report view. It's amazing all the data that it captures during a drive. Here's a 101 km drive from last summer. I'm usually only in EV so it's missing lots of data but this one had the engine on for .par of the drive. The only data missing is the map data that I unchecked before generating the report.

https://1drv.ms/u/s!AqqvKgchnR-Bxmg2ArFUv4w3Nf8n

Edit: OneDrive didn't keep the .html extension. Try downloading the file and add that extension to view it. Don't know why it did that. It's stupid.