EV button and its effect on the HV battery

As a former Gen 2 driver, I will say that a savvy Prius driver can manipulate EV Drive Mode to his/her advantage to exploit the HSD system to improve mpg.

I fully agree that overuse or poor use of the EV button will result in poorer mileage (because the engine will come on to top up the battery, needlessly cycling the battery).

However, with the Gen 2, there are times where you can use the button to force EV mode so that you can glide rather than coast. There's a route where I know the car can glide for a mile, boosting my mpg. But on occasion, the engine will be idling during that section. So, why not use EV Drive Mode, glide during that 1 mile section and then disengage EV Drive Mode afterwards so that I can continue using the HSD system. Sometimes, I can even engage and disengage immediately and the engine stays off.


So it really depends and you have to know your own commute route really well to figure out sections where you know you can take advantage of gliding to boost mpg. The Gen 3's more restrictive EV Drive Mode parameters relegate my use to basically what you described in the first few posts (moving the car to another spot, in/out of the garage etc). The Gen 4 is much more eager to go into EV mode so the EV Drive Mode is rarely engaged (I think I've only done it once so far).