Bad for the emission. The catalyst converter wouldn't be hot enough to be at the operating temp. Prewarm the car in HV mode a mile or so before you need to accelerate very hard. Despite that, PiP emission is still rated AT-PZEV so, we are just trying to stay as clean as possible.
My commute is about 15.5 going to work and 17 back. When I first got the PiP, I used to mess with the buttons to meter my EV. Now, I just leave the EV button on. Checking the trip screen that pops up when I power down, my mileage varies from a low of around 120 with wipers, lights and defroster going to as high as 339 mpg. All this is without trying while I'm concentrating on those around me who are texting at 70mph.
Another benefit of pre-warming is the hybrid system will be taken advantage of. That power-split device seeks out efficiency opportunities. An acceleration that isn't maximum power, like normal merging onto a highway, will result in some electricity being sent to the battery. The result is higher overall MPG.
I got my first look at EV Boost yesterday. Here are the results from the mpg meter. House to freeway – 3 mi of HV (42 mpg) with 13 miles of EV remaining. Freeway 19 miles @ 65 mph in EV (96 mpg) with 4 miles of EV remaining. Suburbs 15 miles in HV @ 30 to 45 mph (82 mpg) with 1.2 EV miles remaining. No chance to plug in & return home in HV (76 mpg) with 1.5 EV miles remaining. So 74 miles of mixed driving with a single charge yielded 76 mpg. The seasoned veterans on PC know about this, but for me the result was interesting. I appreciate the driving tip.
but the thing is, you tried to outsmart the car and ended up hauling around 1.5 miles of EV range that went completely unused. just charge the car, turn it on, and drive. don't worry about the toggles
There are definitely times to use the toggles to get the most out of each of the strengths of HV vs EV. You are right though, you definitely never want to leave juice in the battery if you think a charge is possible at your location.