Rookie Questions on EV Mode

The only time I'd use EV mode is to move the car a short distance when the engine's stone cold, just to avoid a start up. And as often as not, it doesn't work for that, due to various (inexplicable) criteria.

If you had the plug-in Prius electric-only propulsion is viable, but with the regular Prius, using EV mode for anything more than a parking lot shift is "paying Peter to rob Paul", no advantage.

What you can do, any time while driving, and this is outlined in the Owners Manual: lft off the gas, then gently re-apply, keeping the HSI display to the left of center (yellow zone). This will shut the engine down momentarily, and use electrical propulsion only. This is a short term, takes advantage of circumstances (light loads, lower speeds), works at moderate speeds, is locked out above maybe 70 kmh.

And you shouldn't overdo it: once hybrid battery status drops to around 50% I wouldn't actively pursue it. If you do run the battery down, it'll just lock out this on-the-fly electric-only propulsion, and start running the engine even when you're stopped

 

You are correct that what makes frequent or prolonged usage of EV mode ultimately inefficient is that the battery then has to be recharged from a low depleted state from the car engine.

I think for most owners of the standard Prius the times EV mode is actually employed are very specific and precise. To be honest I barely use it. For me it might be if I've parked and need to adjust and re-park. Backing up (moving the car short distances) scenarios. Sometimes when coming home for the final stretch. When I'm driving someone unfamiliar with Prius that wants to "feel" what it is like when the vehicle is running on battery.

But you'll also find that the parameters needed to be in EV mode can also be frustratingly hard to reach. "EV mode unavailable" is a message you will see often. Basically the vehicle has to be warmed up, with enough charge in the battery, and you have to be demanding a gentle enough speed and driving at a degree of slope and incline that isn't demanding a lot of torque.

The major reason I don't often use EV, is that with practice and experience, in most situations where EV would be available if I pressed the buttton? I can "make" the vehicle go into EV mode by just manipulating the accelerator (letting up). So taking the time to press the button to choose the "mode" seems like a waste.

For me there is more value in "Normal" mode...no buttons pressed....ECO and Power...EV as it exists on a Standard 2013 Prius is not really worth it most of the time. EV is the mode I probably use least.

 

The default display, likely what you're seeing since taking delivery, is:

You need to push the display button on the steering wheel a few times, to show the HSI display.

 

1) Yes. The fuel energy temporarily saved by driving on battery power not only has to be repaid, but repaid with interest, because of conversion losses (between mechanical, AC electric, DC electric, and chemical forms of energy).
2)Approximately so, and then only at low speed with no climbing. (Of course you can go much farther downhill, as long as the hill lasts.) Non-plug-in Prii are not intended to be primarily battery-powered vehicles, but to be gasoline-powered vehicles with a modest but useful amount of energy buffering in the "traction" battery.

I generally agree with the above posts. When an EV mode is most needed, usually it is either inexplicably unavailable, or it is available simply by keeping a light touch on your rightmost pedal.

 

The reason there is a battery is to provide acceleration energy. The engine in the Prius is very efficient (relatively) but provides poor low end performance. The battery/MG combination helps overcome this. The EV mode you get into by pushing the EV button is, as noted, not especially useful. However, anytime the car is warmed up and you are doing less than about 45mph, you will go into EV mode (engine off) any time you get the power bar below half way on the system indicator. At this point, your mileage is around 1500mpg, which is why pulse and glide works so well in the Prius. Unfortunately, you are also slowing down and have to eventually accelerate, which is why you don't get to keep the 1500mpg.

 

When engine stops, shift into "N" works too.

Bob Wilson

 

Well almost. Just to qualify that: if you've got all the above conditions, then lift off completely on the gas, then gently re-apply, keeping to the left of that halfway mark, you got very good odds of the engine shutting down, using electric propulsion only. And yeah, even without the lift-off-and-reapply tactic it'll sometimes shut the engine down.