Using EV

Because ultimately, ALL power comes from the ICE and anytime you have to recharge the battery, you have to convert mechanical energy to electrical energy (resulting in losses of energy), convert that AC voltage to DC voltage (resulting in losses of energy), store that energy, then convert DC to AC (resulting in losses of energy). The best mpg can be obtained by converting the least amount of mech energy to elec energy and vice versa. The brake is your enemy, use it the least amount possible.

 

Because they turn the ICE off at every available opportunity and they recapture energy (through regenerative braking) other cars simply lose. Even with all the losses involved with conversion of energy, it is still much more efficient than throwing it away (as the Fit does).

 

As you've noticed, the car often shuts the engine down and runs electric-only. Even the Owners Manual has tip for triggering this, saying to lift off the gas and gently re-apply. At lower speeds you'll typically stay in electric-only as long as you keep the Hybrid System Indicator display to the left of median (yellow zone in pic). I would just be careful with it, use it while state of charge is high, but once it falls off to about half-full not so much.

 

The type of internal combustion engine is different in the Prius!
It is a Atkinson type engine which is not so good at low end torque. They make that up with help from the electric motors when needed.

 

The battery/regeneration system is mostly misunderstood. There is little or no "cost" associated with regenerated energy. The efficiency of the system is why the car gets better mileage in town than on the highway. It is also one of the major reasons the car gets such good mileage in general. The regen systems and the Synergy firmware represent about 2/3's of the cars efficiency increase. Using a true glide with the EV car up on the system indicator is the best way to maximize mileage. Don't try to out-think the systems, the car will take care of the battery charge.

 

When you buy a Prius, one of the hardest lessons to unlearn is the battery is part of the transmission and not really a primary power source. It buffers the engine so the engine can operate at maximum efficiency WHEN NEEDED and otherwise it is off. So the higher City mileage comes from lower City speeds with less energy lost overcoming drag. You can experimentally verify this.

Drive a week in "D" and another week in "B". In "B" mode, the engine runs nearly all the time, even when coming to a stop. You're City mileage will take a big hit depending upon route.

Bob Wilson

 

I only really use EV move when moving the car out of the garage to wash it, back in and to switch stalls when I don't want it to go through the start-up routine. After all, it's just going to cool off and go through the routine again the next time I start it to go somewhere. All other times I let the system decide when to kick in EV mode.

 

Thanks for explaining how B mode works in the non Plugins. I use B mode all the time in my Plugin and the behavior is much different while in EV mode.
With the Plugin switching to B mode while in EV mode is almost exactly like downshifting a manual transmission. B mode also provides more regen as opposed to D mode. And with the Plugin in EV mode, one very rarely needs to worry about overcharging the traction pack.
All the above will most likely be completely different when using the Plugin in HV mode. So many things to test, so little time to get to each one of them ...

 

EV helps when done right. The car is already very intelligent with this, and does it right the great majority of the time.

Done wrong, EV hurts. Because the car already controls it very well, it is far easier for ordinary drivers to do less well and sabotage MPG, than to do better than the ECUs and improve MPG.

Yes, the driver can do better. But it takes significant experience. If you want to try to outsmart the car, be sure to get a very good baseline without forced EV, so that you have something to compare against. It may take a lot of effort to get even small gains.

 

An interesting advantage to the PiP? Your B Mode regeneration goes to the traction battery instead of powering an MG to spin the ICE with ignition/fuel disabled? Probably up to some specific SOC since the PiP has a larger battery? I know very little about the PiP.

 

First when I got the Prius thought the EV button was useless, but now I am using it and I found it useful.

Situations where I force the EV.

1. Driveway where I need to move the car in or out in the garage.
2. Vehicle parked. Battery is full but the engine is still on, so I force the EV.

 

This statement is wrong. It is correct to say that the ICE is not efficient at a steady state power demand to move the car at 25 mph on level ground.

Let's say it takes four kW of constant power for the above. The smart alternative is (in kW):
12 .. 0 .. 0 .. 0 .. 12 .. 0 .. 0 .....

P&G -- pulse and glide. Ask Google to learn more

 

How much more powerful is the EV engine for the PIP compared to the non plug in?

 

The motor on the PIP has exactly the same specifications; 60 kW (80 hp), and 153 foot-pounds of torque.

The difference lies in the battery - in addition to having a little over three times the capacity, it can produce about 40% more power; 38 kW instead of 27 kW. (50 hp instead of 36 hp, if you prefer.) Both vehicles will send some power through the electrical system when using the gas engine because of the way the HSD works, which is why the electric motor is more powerful than the battery. The work done by the engine is split between driving the wheels and driving one of the MGs as a generator; this power is then sent directly to the other MG which is acting as a motor.

 

I've long wondered if a 'lock' on the flywheel would allow both MG1 and MG2 to operate in parallel. Then use silicon-carbide, power electronics to improve efficiency, and adding a little more EV range. So some light-weighting, a nice package.

Bob Wilson