[SyZyGy]

How fast can the Prius go with only the electric motor in use, (Without the EV mode modification switch) without the ICE kicking in?

 

[Victor]

How fast can the Prius go with only the electric motor in use, (Without the EV mode modification switch) without the ICE kicking in?

not far and slow!

With the EV switch upto 2 KM on a level road max speed circa 50Km/h

 

[john1701a]

Stealth has a maximum speed of 42 MPH.

I find 40 MPH pretty easy to maintain nowadays. It does take some practice though to figure out how to keep under the 10kW threshold though (that's how much the battery-pack allows you to draw while in stealth).

 

[BIF]

I try to do it in "stretches" when I'm driving around town and the traffic isn't too heavy (I often drive home at odd hours, when there is little or no traffic, and I can maintain a speed of 35 to 45, give or take).

Sometimes, I'll drive with the intention to "charge" until it gets to 6 bars (highest blue).

My ultimate goal is to drive for as long as possible with the instant MPG reading > 50 MPG. I try to do this, regardless of whether she's charging or going on electricity only.

Traffic and traffic lights permitting, I may be able to "drive-and-charge" for 2, 3, or 4 miles, with the occasional slowdown or stop. At some point (while charging), it will either go to 7 bars (green) or not. Either way, sooner or later, she'll really resist further charging, and will actually change her mind (just like a lady) and want to discharge. This is easy to tell, because it'll go from engine + charging to either ICE and Electric or Electric only.

At this point, the computer's "bias" has changed from "want to charge" to "want to discharge," so I'll take advantage of it, and drive in stealth for as long as traffic and the computer will let me. Might as well use it up, as far as she'll let me (usually down to 5 bars <one above half> or 4 bars <half>, depending on my speed, grade, wind, and her effort.

I might only get a half-mile in stealth, or I might get a mile, or maybe longer, depending on grade and wind. Eventually, she'll change her bias back to "want to charge," so I will adjust my foot again for charging, and try to keep geting > 50mpg on the instant display.

So my driving goes sort of like this: Charge until she resists. Stealth until she resists. Charge until she resists. Stealth until she resists. Repeat. Slow down or stop for traffic as necessary. Speed up gradually, but try to do it "with charging," because I'm using gas anyway to accellerate...might as well put the HSD to full use and charge her up for another leg in stealth mode.

It's still fun, and actually, I hardly think about doing all the above. It's just natural now, and I do it without a second thought, and with hardly any glancing at the MFD.

 

[efusco]

The answer to the original question is 41mph. At 42mph the ICE will always kick in.

FWIW, with the EV button the max speed before the ICE kicks in is 34mph.
--evan

 

[john1701a]

41 MPH may be the actual speed, but it won't always be what you see on the speedometer. Worn down tread changes the rev count a little bit. Alternate tires do too.

 

[RSnyder]

If the total requested power is less than 10 kW, the Prius can run at any speed with just the electric motor powered by (or regenerating power to) the battery. Above 41 MPH, the engine must spin, but it doesn't need fuel unless the Prius has decided to get power from it.

 

[ken1784]

FWIW, with the EV button the max speed before the ICE kicks in is 34mph.
--evan

Please note that the 34mph is the speed where the EV button is canceled.
It does not mean the ICE always kicks in at that speed. We can continue to run in stealth.

Regards,
[email protected]

 

[efusco]

FWIW, with the EV button the max speed before the ICE kicks in is 34mph.
--evan

Please note that the 34mph is the speed where the EV button is canceled.
It does not mean the ICE always kicks in at that speed. We can continue to run in stealth.

Regards,
[email protected]

In theory, yes, that's true. But.....

I've never once stayed in stealth over that speed. That said, I very rarely go that fast using the EVb either. But, to get to that speed will put a very large drain on the battery and continuing above that speed in stealth will be very unlikely unless you're going down a hill. Even then, if the SOC is low enough the ICE will, more than likely, kick in.

Thus, although I agree it's theoretically possible that one could stay in stealth when the EVb mode cancels I think that 1)the algorhythm for the system probably forces ICE on, 2) SOC of the battery would cause the ICE to come on if still accelerating to a speed above 34mph.

 

[ken1784]

I've never once stayed in stealth over that speed.

It is easy to reproduce on a downhill.

Regards,
[email protected]

 

[efusco]

I've never once stayed in stealth over that speed.

It is easy to reproduce on a downhill.

Regards,
[email protected]

Ok, I did it this morning on a downhill...had the top blue bar on battery SOC, easily got up to 34mph in EVb mode and just kept going until I had to accel up the next hill. Still think it would be darn hard on anything other than a downhill run.

 

[DaveinOlyWA]

so it sounds to me that a certain combination of speed, gear ratio, and torque will control whether you can stay in stealth.

we have a lot of hills where im at so i frequently stealth at 65 mph but always on a long gradual hill. but if i can maintain the speed using only a little car power and a lot of gravity then the speed does seem to go up.

on level ground at times i cant stay in stealth even at 35-40. it all depends on SOC and other stuff im not wholly sure of.

 

[ken1784]

we have a lot of hills where im at so i frequently stealth at 65 mph but always on a long gradual hill.

It is not a pure stealth but in a fuel cut mode.
Please note that the ICE is always running faster than 42 mph.
Bad thing is the MFD does not show the ICE is running in such situation including with it's warming-up period.
The MFD only show the ICE is WORKING.

Regards,
[email protected]

 

[DaveinOlyWA]

oh course the ICE is running, but it is not contributing enough energy to show on the display. that is stealth mode.

 

[ken1784]

oh course the ICE is running, but it is not contributing enough energy to show on the display. that is stealth mode.

http://john1701a.com/prius/prius-stealth.htm

John's definition is...
"Stealth is a special feature of Prius. It's the ability to drive without the engine running, using only electricity."

Regards,
[email protected]

 

[DaveinOlyWA]

that would be EV mode

 

[efusco]

Ok guys, first of all none of this stuff is "Official" terminology, so nobody is going to be declared a winner.

But the wider accepted definitions are:
stealth : running on battery only--no ICE activity at all (i.e. <42mph)
hyperstealth : ICE is spun up but not contributing power (fuel shut off)--speeds in excess of 41mph
EV mode : Running on battery power only after engaging an EV button

Define how you prefer, but 'most' people use that terminology these days.

 

[BIF]

Ok guys, first of all none of this stuff is "Official" terminology, so nobody is going to be declared a winner.

But the wider accepted definitions are:
stealth : running on battery only--no ICE activity at all (i.e. <42mph)
hyperstealth : ICE is spun up but not contributing power (fuel shut off)--speeds in excess of 41mph
EV mode : Running on battery power only after engaging an EV button

Define how you prefer, but 'most' people use that terminology these days.

Add to that one that I call "superstealth", which would differ from your hyperstealth above. Superstealth would be, plain and simply, "gliding" with no power being contributed either from the ICE or from the electric motor-generators.

In other words, "no arrows" on the MFD, yet the wheels are turning.

Sometimes, I am a veritable sailor in my Prius. If I can catch the wind just right and maintain my speed without gas or electricity, I'll do that for as long as possible. Depending on traffic (and traffic light) conditions, a slight slowdown might be acceptable or even preferable.

I think of superstealth as "truly free" mileage. I can often go 1/8 to 1/4 of a mile in "superstealth", sometimes more.

 

[efusco]

Ok guys, first of all none of this stuff is "Official" terminology, so nobody is going to be declared a winner.

But the wider accepted definitions are:
stealth : running on battery only--no ICE activity at all (i.e. <42mph)
hyperstealth : ICE is spun up but not contributing power (fuel shut off)--speeds in excess of 41mph
EV mode : Running on battery power only after engaging an EV button

Define how you prefer, but 'most' people use that terminology these days.

Add to that one that I call "superstealth", which would differ from your hyperstealth above. Superstealth would be, plain and simply, "gliding" with no power being contributed either from the ICE or from the electric motor-generators.

In other words, "no arrows" on the MFD, yet the wheels are turning.

Sometimes, I am a veritable sailor in my Prius. If I can catch the wind just right and maintain my speed without gas or electricity, I'll do that for as long as possible. Depending on traffic (and traffic light) conditions, a slight slowdown might be acceptable or even preferable.

I think of superstealth as "truly free" mileage. I can often go 1/8 to 1/4 of a mile in "superstealth", sometimes more.

I usually just call that 'gliding'. BTW, while we're on terminology, Deadbanding refers to ICE powered driving with no arrows to or from the battery--generally considered the most fuel efficient mode since there are no energy losses in conversion to stored battery power and back to kinetic energy. The down side is that there is not a lot of power from the little 1.5 liter Atkins cycle engine.

 

[jshore]

EV mode : Running on battery power only after engaging an EV button

Hate to be ignorant here after having my Prius for over 4 months already but what is the EV button?