Backing up on EV mode only

Turning on the Engine at startup always has to do with emissions, and in fact the Prius never uses the engine as motive power in reverse. There is no reverse gear, so the engine always turns forward. To emulate reverse, the electric motors run backwards and provide all the motive power.

 

Prius starts the engine after 10 or 15 seconds. If you are quick and reverse as soon as possible, the engine wouldn't start until after you drive away in D.

 

The engine will run more often in cold weather to keep the emissions equipment warm. This is to make sure it is functioning properly. When the engine fires up in reverse at those times the driven by the outside temperature.

 

Yes, this is the one EV mode that's always there. That's comparing to the EV Button, which has about the same odds as a scratch-and-win ticket.

 

This is incorrect. The Gen-3 v models will ALWAYS start the ICE in reverse unless the ICE is warm.

 

15 second EV mode.

 

Depending on the state of charge of the HV battery, I've had success backing up without the ICE if I put the car in EV mode right after I push the START button (well, a few seconds after). If the HV battery state is down 3 bars, it will not work. But just backing up right away doesn't stop the ICE from starting up.