As sure as I can be without seeing the source code. If my 30-mile average whpm is high, I observe rates like 18 MPH (2 hours into the charging session). The next day when I have a more reasonable whpm, I observe rates like 25 MPH. Same voltage and amperage.
This is all since 4.0. There's a mismatch between that calculation and the rated/ideal setting (which used to be projected/rated -- so it feels like the code doing the math never got changed away from doing projected to doing rated when that switch is in the left-most position). Doing the math with respect to whpm and how that would affected the MPH charge rate works out, too.
I covered this in more detail in another thread (too lazy to find it :smile
but I've been closely observing this (I'll leave it up to everyone here how I'm doing that) just about every day.
Right now I'm at 19 MPH with a high whpm from the 20F temps for this evening's commute home.
Edit: in case you didn't run 3.x before, 3.x used to show projected MPH charge exactly like it is now with that switch to the left (which used to be projected/rated). I think they forgot to update this bit of code with the 4.x update.