Snow traction

A few.

 

Toyota also took their "fantasy" and wrote it down in computer code, and burned it into chips in the ECU that takes the accelerator pedal position and calculates the power requests sent to the electrics and the ECM. It's not like they were sitting at their desks fantasizing while outside of their knowledge the car got built some other way.

"In Real Life" means a bigger ball of yarn than you're letting on. Real life includes both what Toyota has explained about how the machine is built, and also whatever personal observations you have from driving it, with or without your buddy with the stopwatch. (It also includes whatever other measurements, of pedal angle, SoC, battery and inverter temps, etc., could also have been taken at the same time.)

It's not so uncommon that real life includes pieces that are at first hard to make sense of together. That can lead people to scratch their heads for a while, maybe figure out what additional data need to be collected, and sometimes reach a more detailed understanding of how the reported observations might have been obtained from a machine that is built this way. So we end up understanding real life better.

Trying to skip over that process by playing word games doesn't accomplish that. Saying "I'm just going to use 'theory' or 'fantasy' for the part of real life where the builder explains how the machine is built, and I'll use 'real life' to mean my handful of personal observations and whatever I think is the right way to explain them" doesn't end up leading to much usable new understanding, because the head-scratchy part where the learning happens is the exact part being skipped over by the word games.

 

Reality is as we perceive it and is often different for every observer based on their experience, logic and current state of mind.

“Every kind of ignorance in the world all results from not realizing that our perceptions are gambles. We believe what we see and then we believe our interpretation of it, we don’t even know we are making an interpretation most of the time. We think this is reality.”
~ Robert Anton Wilson

“We don’t see things as they are; we see them as we are.”
~ Anaïs Nin

 

Through out my career, I worked with systems that were designed to perform 'X' task but the operators were not able to get the systems to do that task. Thankfully in my careerfield we usually had access to company Tech Reps to observe how each system performs, to advise the operators and to continue the forever process of re-designing the products.

I entirely understand the idea that engineers design things to perform in a specific manner, and at the same time when that system is put into production the design fails to perform in the manner that the engineers thought it would.

To say that the designers manual is reality, is in itself far from reality. The designers manual is the drawing board, it is what the engineers dreamed for the product.

 

I haven't seen Toyota publish "designers manuals". The manuals they do publish are better described as closely reviewed, detail-for-detail as-builts.

So far, the number of mistakes (even as trivial as a misprinted terminal number or one mistranslated word) I've ever found in Prius manuals could be counted on the fingers of one hand, still leaving enough to pick up a baseball.

It's possible that the career experience you're describing is a lot more like mine, where rather elaborate, somewhat bespoke systems were being developed and deployed, and the tech reps were on hand doing further design revisions while the operators were already at work using the stuff.

Toyota's in a mass-production game; it's a little different. They are pretty much committed on how they are going to build the thing when they are commissioning the production lines to churn it out. The relatively small number and narrow scope of changes between years of a generation, and even appearing in TSBs, bears witness to that.

They have to be getting their technical docs to their dealer mechanics on TIS in the same time frame, and not vague or unproofread fantasy versions.

 

No more upping the ante, I'm going to call.

Could you please post the difference in times recorded by your passenger and over what distance?

Were these multiple runs down the exact same pavement, back-to-back, to account for any grade, wind, temperature, etc.?

And I guess I'm most interested in.....you're driving around with a friend -- what exactly was going on that caused you to say, "Hey, let's go run quarter-miles switching between PWR and ECON! You time, I'll drive. Let's do it many times!"

 

An angle that might be getting missed here:

I had understood that ECO mode also adds some filtering to the throttle control. Can Chap confirm this? This necessarily adds a bit of time delay, which some may interpret as 'sluggishness'.

It would make sense that people measuring acceleration times from an idle throttle would see this ECO-mode added delay, added to their measured times, even if the actual engine power is identical. If this is what is happening, then the acceleration distance would not show an equivalent change.

I must say again, people who actively measuring this, are most definitely not driving on real snow.

Like Chap, I explicitly avoid PWR mode in snow. Fast response of high power is a recipe for ice polishing, not for traction.

 

That's not something I remember reading anywhere (which doesn't necessarily mean it's not so). I'm at a bit of a loss to think of an easy way to test it; Techstream's polling interval is probably too long to reveal much at the time scales of interest.

Some kind of passive CANbus sniffer that could eavesdrop on the power-request messages going out from the power management control ECU in real time, maybe, plotted alongside the position voltages from the pedal sensor.

 

This video, posted very long ago by a moderator who is still here, doesn't address my angle because it doesn't show the driver's foot on the pedal, or equivalent. But it does otherwise address 0-60 times, PWR vs ECO.. Who has a good stopwatch?:

0-60mph ECO vs. PWR | PriusChat

 

No stopwatch, but by the time indicator on the YouTube player I see no difference. It doesn't have fractional seconds (and youtube is soundless on this box).

Somebody with an up-to-date youtube-dl could probably download it and find the frame at which the pedal sound is first heard and the frame that first shows 60, and that would beat trying to time it by poking at a stopwatch.

 

I was doing some measurements on my 2009 Prius 3 and at some point (2021-09-01), simply out of curiosity, I decided to floor my Prius (what I do not do very often) and measure the real life acceleration.

As I drive in ECO all the time, I suppose, it was measured in ECO (although there is no proof for it).
Below you can see the measurement.



I actually am not willing to do it again - it is winter here (south Poland), and the equipment is programmed differently now.

Regards

Mat

PS. The image seems to be re-sampled - I uploaded it with more details

 

>> "Error - edit time elapsed"

PPS. I'm not pointing the start and stop times - this pointers point to the time intervals on the time axis, so you can read it on the downsampled image.

And another one
I see now, the time is measured in milliseconds - not microseconds.
The time 0-60MPH is approximately 10400 ms (10,4 s) and the time 0-100 kmh is about 10900 ms (10,9 s).

 

What's the story with all the bouncing gas pedal position before the speed curve begins to rise? Were you goosing the gas pedal a few times before releasing the brakes?

 

I did not want to start with 0 RPM on the ICE, so I gave it a little gas pedal action to start the engine (with the other foot on the brake), so thhe system did not have to start the ICE accelerating from 0 kmh

Mat

 

I do not know anything about filtering of the throttle signal in ECO, but I can imagine, that in POWER the internal combustion engine (ICE) stays running more often, than in ECO, so the "ECO-sluggishness" could be a result of this.

Driving in ECO the ICE would shut off more often, thus, if you quickly demand high power output, the system has to start the ECI first in ECO, what it often does not has to, if you are in POWER mode (the ICE is running anyway).

I would see here the reason for the perceived "sluggishness" in ECO - not in the system power restriction (what in my opinion is not happening).

Mat

 

I agree with you Mat. The disputed claim was that wide open throttle from closed throttle position gave different results in ECO and PWR, with alleged passenger timing to support the claim.

 

Turning off traction control in snow/mud should help too. Pretty sure that it does not goes all the way off anyways.

 

Turning off traction control will often be a way to earn ice-polishing awards as shown in the third video linked in post #3.

When you compare that to the two earlier (successful) videos in the same post, you can clearly see the operation of the traction control in the earlier two.

 

If you're really unlucky it might damage the transaxle too?

 

You must have had no choice! I'm subscribed to WSDOT alerts for I-90 and I would be very wary of even going past North Bend at this point. It seems they keep closing it for spin-outs or avalanches.