Why do I use the electric drive only if I depress the accelerator pedal completely and then reapply force? Shouldn't the electric drive kick in if I am traveling at ~30 MPH on a straight road with HSI showing the bar on the left side? Am I damaging the ICE by forcing the electric drive?
I'm not sure what you are asking, but you can't damage the car by driving it. Unless, of course, you drive into something. If you are asking if electric power is used if you just accelerate normally, yes it is, but only some is used. Switch your display to see the arrows going to and from the engine/motor-generators/battery. You will see electric power is in fact used all the time when needed. The car will use the motor generator to supplement the engine in just about any initial required surge of power. This includes a gust of wind increasing drag while on the highway under cruise, starting out from a stop, accelerating (you apply the accelerator), etc. The engine will be started and used if this required surge of power is longer than a few seconds or greater than the motor/generator can supply. If the engine was running when this surge was required it will be used in parallel with the electric motor/generator. You can force electric only drive in certain situations, but the car will not let you damage the battery or electric motor/generators. For example, you turn on EV mode, then try to drive, using more power than the car is set up to allow to protect the systems. It will kick you out of EV mode in that case. The HSD (Hybrid Synergy Drive) will not allow you to damage any part of the system. You can't over-rev. the engine, you can't use too much battery current or charge. It will even complain loudly if you try to run it out of gasoline (but it won't stop you from doing so).
Thank you for the great explanation David. Let me try rephrasing the questions. I am travelling on a road at 37 MPH with both the electric drive and the gas engine. Even though I am on a straight road and travelling at a consistent speed, the electric drive will not come on unless I force it. By that I mean, I have to completely release the gas pedal and then reapply force. When I release the gas pedal, my MPG shows 99 MPG and the HCI shows that I am in EV mode. Now the question - why does the car not enter EV mode automatically even though I am traveling at 37 MPG on a straight road? I am not using much force to maintain the speed.
The car will make a decision on whether to run the gas engine or not based on a number of factors, including battery SoC, speed, demand (accelerator position), engine temperature, etc. When you release the gas pedal, it decides to turn the engine off because of reduced demand, and when you press it again, it decides demand isn't high enough to turn it on again. It could be that it was charging the battery before because it was a little low, for example. Being in the lower half of the HSI is more likely to use EV only, but not guaranteed.
Ah, that makes complete sense. Now back to my original question - Am I damaging the car in any way by forcing EV mode by using the technique mentioned above?
No, but you get better overall gas mileage by not forcing running in EV mode. There is energy loss (heat is generated) when you charge or discharge the HV battery. JeffD
what kind of car do you have? if it is a prius, you can increase your mileage by using a technique called 'pulse and glide'.
I have a 2012 Toyota Prius. My question was pertaining to 'pulse and glide'. When I am releasing the gas pedal and going into 'glide', I force the electric drive to come on. My commute is 100% city and I never exceed 40mph. From my knowledge in engineering I always thought you could damage the car and waste energy by releasing the gas pedal.
no, you cannot damage the car. the toyota engineers outsmarted you, if you can believe that. there is a very tiny spot on the pedal that is a true glide where you are not accelerating in ev and not regenning. it is right at the apex of ev and regen. it's hard to spot on the power screen, but if you watch the hsi, it's right on the power/regen line. if you had a scangauge, i hear it's a bit easier to find.
