There are two MPG counts on the rcf. Screen one says after reset and screen three says after refuel. Which is the most accurate?

 

I changed one of them to "After Start" so it shows the MPG from when you start the engine to destination.

 

One is the total average since the last reset while the other one is since the refuel. This one automatically gets reset once you refuel. I use it in my RX450h (in RCF, it is my fun car so there is no point in looking at it), I want to measure the fuel economy from full fuel to almost empty so I use 'since refuel' as it is more useful since driving style after every refuel is different.

 

nice! That's what I thought the others were doing, it seems more useful. How did you do that??

 

Below the "4 Square" rocker is the menu button with three lines.
When pressed the Driver Information Center - DIC usually defaults to an MPG display.
Press the 4 square rocker left to move to "Settings" identified by the "Gear" icon like your phone settings
Press the 4 square rocker down to move to Drive Info 1 & DI 2, use the white dot in the center to open.
Choose which parameter you wish to see and then back out using the "return arrow" button next to menu.
Note: to change the default display when you initially press the menu button...
scroll through the screens to display your choice, press and hold the menu button, answer yes I want it saved.

 

I use the since refuel setting. That one is the most useful since it gives you the average over a full tank, similar to resetting your trip meter every fill up and manually calculating MPG. Has a more immediate affect on spotting issues.

Per-trip can vary wildly, especially on short trips. About as useless as that instant MPG readout (going uphill is 10 MPG, but coasting down it is 80 MPG, neato - I guess).

The "since reset" setting is just an aggregate since whenever the last time you hit the reset button. Might be useful to tell long term driving habits or if tracking a long road trip, but I still find the per tank method the most useful since it's a sample over a narrower range.