I am pretty sure in my hch2 that the A or B average MPG indicated is just that - the average since the mpg was reset....

So, no matter if the sampling rate is high or low - I think it updates ~5 seconds, its just your average mpg. Certainly, as you add miles to the average without a reset, its more difficult to raise/lower the average.

 

Amazing! What kind of terrain & roads do you typically drive on?

My mpg has dropped significantly since starting this tank (as we all knew it would), but I'm doing better than I ever have at 55mpg 305 miles into the tank. I'm sure the warmer weather has something to do with it. Unfortunately, a good bit of my commute is on hilly interstate. I manage to creep along in the slow lane at around 57-58, but I can't do much about the hills.

 

I haven't hit my reset button on the B trip since purchase. I can get it to move one way or the other in less than 20 miles indicating to me that there is a cap on the sample size. I have over 80K miles on the car.

 

The best I've seen is 150.0 mpg (downhill, of course!). It's odd that the car is programmed to not display anything greater than 150.0 mpg. Does anyone know why they would do that?

 

My 1996 Jag had an instant MPG display, and it maxed out at 99 MPG. THAT was probably done so they could use a display with fewer digits (2). Not sure why the Civic's is limited to 150, when 999 will fit in the same 3 digits. Maybe Honda doesn't want us getting too optomistic (or too crazy in our efforts to max it out).