[egmacrae]

Usually when I am in EV mode on my PHEV, the drive information mpg is 999.9 until I've used up my 26 electric miles. Lately it has been showing me 50-90 mpg when I still have juice in the battery. Did i accidentally change a setting or has something gone wrong.

 

[brandent]

That means the gas engine kicked on at some point either by
a) you accelerated hard (anything over about half throttle).
b) it's fall and getting cool. in EV mode the engine will turn on if heat is called for. It will run the engine steady at about 2000 rpm until the coolant is hot then shut off. During that time the engine charges the battery so it is in fact using the most efficient possible gas burn.

 

[flroots]

I don't find the dash MPG displays particularly useful. Fortunately, and as discussed elsewhere, I can use my OBD2 scanner in conjunction with the Torque Pro app to record and calculate various PHEV parameters. My goal was to calculate MPG during the following intervals:

1. While engine running
2. Overall trip average

As can be seen in the graph, those two calculations are much different. Unfortunately, I have not found a way to isolate periods in which engine is running by itself. I believe there was a brief period around X-value of 300+ during which both motor and engine were adding torque due to the rapid acceleration in speed. This is probably what caused the brief spike in MPG. My formula sets Engine MPG to zero during periods in which the engine was off.