Engine more refined in Power Mode

I'm not going to say the OP is either right or wrong.
I think only a Toyota engineer might actually know.

I do know that in all my years I don't remember any statement from Toyota that the power mode for The Prius worked in this manner:- " Power mode the electric motor is programmed to take on a greater share of the load earlier compared when in the other modes."- As is the OP' s thought and contention.

Also since the ultimate "proof" of this happening is at this point presented as a "more refined" feeling and sound?

Well, all I can say, is the few times I employ Power Mode, it clearly "seems" to accelerate quicker if only because of the remapping of the accelerator pedal input. But I don't necessarily equate that with being more powerful or even more refined than Eco or Normal mode.

Honestly my opinion (which could be wrong) is that if I push down harder and faster on the accelerator in either ECO or Normal mode, I can pretty much duplicate the "feeling" and acceleration possible in Power mode. This would suggest to me that no real additional electric motor power is being applied.

I could however be wrong. And I think the idea is an interesting contention. I think the only real answer would be a Toyota Prius software engineer, telling us either "Yes" the electric motor assist is handled differently in Power Mode, or No, it is not. Until that type of definitive statement, all we get is arguments over perceptions and feelings such as "Smooth" and "Refined".

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Tested the contention of the OP yesterday afternoon. Both eco and power modes have the same delay to start the engine from a stop. If you're asking me to notice a 0.2 sec difference -after- that good luck! It might be possible with test gear. My butt dyno is not that accurate.

As far as the Lexus, the programming is different, so even if the hardware were exactly the same (which I doubt) the car will perform differently. Saying the 0-60 times are the same proves nothing. Could be a fluke, could be real. The Lexus is heavier, so probably has more power, which could prove the two cars are different. Toyota/Lexus have stated in the past the Lexus hybrids are tuned for more power, whereas the Prius is tuned for best mileage. So they should be different.

What I -don't- see is a "more refined" engine response. Different perhaps, but "more refined"?

 

I'm impressed with the original poster's engineering way of thinking. I only know enough about PID controllers to be dangerous. It seems to me that you can't over simplify and there may be some difference from the expected first order solution.

 

All I know is Power mode makes it like a whole other car. It certainly seems way faster to me, and is definitely more responsive.

 

Thanks for posting.
10s 0-60 times for either mode. I didn't see or hear any difference.

I personally use the normal mode only. First, I can't stand the green lights; second, normal gas setting is the easiest one to modulate for pulse&glide.

 

Seems to me the difference is not when you floor it. It's when you are less than flooring it, Power mode gives you a lot more power/responsiveness.

 

Exactly, you get more power for less pedal in the Power mode. But that's the only (main?) difference. You can get the same power for slightly more pedal when not in the Power mode.

 

I kind of suspect that it's mostly self inflicted psychological illusion that the vehicle is more "refined" or "smooth".

Because of this thread I purposely used Power Mode on a few merges onto the freeway. The vehicle because of the accelerator pedal remapping is definitely more responsive in the form of reacting much quicker.

My speculation is however that what is really happening, is in reaching the speed you need or want quicker, you are consciously or subconsciously also letting up on the accelerator to slow down or level off, a few beats quicker, thus creating the illusion that the vehicle is operating with more refinement or smoothness.

While conversely if in Eco Mode or "Normal" the reality that you have to push the accelerator pedal down farther to get the same response level, creates the "illusion" that the vehicle is struggling to reach speed as quick, even though in reality you are dealing with the same Prius Power Train as before....nothing really has been changed outside of pedal remapping.

But again, honestly I don't know. The idea that more electric motor assist is provided? Is an interesting idea.

 

EZ solution. Someone put their 3rd Gen on a DynoJet.

Mike

Mobile on my SGH-i717 now Free

 

I agree. The perception is that Power mode is quieter getting up to speed. It seems to be more than just a different throttle mapping. If I floor it in normal mode, the ICE appears to reach higher RPM sooner than when in power mode. It could be purely psychological. Only Toyota engineers can say for sure.

 

And they did say, at new model introduction events before the GenIII reached the U.S. market.

But that hasn't stopped more than 4 years of other speculations and opinions on the subject.

 

Any transcript of the event?

 

Numerous leading PriusChaters (not me, I had just barely joined) attended the Prius Connection Detroit event in 2009 and were able to speak directly to the engineers. Here are two threads easily located by Subject, but there were many more related threads active at that time:

Prius Connection Detroit Photos
Toyota posts 5 videos from Prius Connection Detroit on YouTube

 

I've had my 2013 for a few months. All I can say is that between ECO and POWER modes, the car behaves like two different vehicles. I use POWER when driving in NYC traffic due to the immediate response of the throttle when dodging taxis and pedestrians. I use ECO on the highway and so far it has worked out for me. I have to say that POWER mode definitely gives the illusion of the car having more PEP than in ECO mode.

 

Yes, I have to agree. I paid particular attention during the release of the 3rd Gen, and at the time there was a lot of interest in exactly what these new "modes" were all about.

Now could I have missed it? I suppose....possibly.
But I do not remember any mention of Power Mode offering greater electric motor assist.

I'd also think from Toyota's standpoint if that was the reality, they would want to mention it. They would want you to know what differences exist. I can remember no statement from any Toyota engineer, designer, or official representative that proclaimed that Power Mode offered greater electric motor assist.

If somebody can find evidence of this, I'd be happy to stand corrected.

 

For kicks and giggles, I've written to Toyota in Japan. If I get any response at all, I'll post here.

 

I don't remember any mention on that part either, then or since.

But OP also mentioned feeling a difference in the time lag between pedal position and throttle opening, which is a different thing. While I don't remember anything explicit about it at introduction time, it is consistent with the 'more responsive' statements, and fits with additional descriptions that came out later. It is also consistent with how I can put a twitchy foot on the pedal and find that twitch filtered out in ECO mode.

 

Toyota wrote back that they want my VIN#, so it's on to the next step.

 

In my experience pwr and normal mode feel about the same at WOT from a stop, although there is that half a second delay (i'm assuming programmed in to protect the drive train), and unless the pavement is nice and sticky there is usually a little tire chirping. I agree though on the smooth(luxury like) feeling of WOT acceleration in the Prius. I admit to indulging on the occasional highway merge. It may be 2 seconds slower than a yaris 0-60 but it feels so smooth and refined compared to any stepper gear ICE automobile.
Could the sensation of "refinement" also be related to the traction battery's current SOC?
Living in a hilly area and regularly experiencing the difference of an "indicated" fully charged battery, a "normal" SOC, and a severely depleted "2 bars remaining" SOC I have noticed subtle differences in the power output and ICE noise relative to current SOC of the traction battery, regardless of "mode" selected. Accelerating with an above normal SOC will result in a more refined sound to the ICE as its doing less work to accelerate as the Prius "brain" is trying to use up the excess SOC to allow for the next regen opportunity. I have to keep reminding myself to not rely on the sound of the ICE to judge speed and acceleration as sometimes the ICE will sound like its hardly doing anything yet my speed is in fact increasing just as it would with a louder ICE at another time and place with a lower SOC.