In a recent post about EV mode, some replies said EV mode wasn't efficient? I was driving in Santa Monica, CA today and a closed freeway on-ramp had traffic a mess. I didn't go over 20 MPH for 8 or 9 blocks and it took about 15 minutes to get through. I was sitting there wondering if I would put the Prius in EV mode?
well... if your prius is warmed up.. it will use EV for the most part. the ICE will kick on to assist.. but any time you start coasting, it should switch off. using EV may just drain your battery and leave your engine idling to gain bars.. no top of that your next couple miles of driving will be lower due to battery charging. i'm not driving for gas mileage.. so i use EV in situations like those. If F.E. is your goal, don't use EV unless your coasting down your driveway or other residential area.
That might be one of the few situations where I would use EV for propulsion, at least in part. Yes, overall it is inefficient to force EV because of the need for the ICE to run to recharge it. But if you're in a situation where the ICE has to repeatedly light for short (i.e., just a few seconds), low-demand bursts, then if you can keep your speed fairly steady at a very low speed it might be more efficient to run only on the battery until you're through it. (There's also some evidence to suggest that helps traffic flow more smoothly overall.) Let's say you can hold it at 5 MPH. Just a small amount of EV will keep it going at those speeds. If you choose (or are forced by latent road-ragers on your butt) to repeatedly go from a dead stop to 20 MPH and back, then it's probably more efficient to run the ICE.
