0-60mph ECO vs. PWR

No, the gear ratio is always exactly the same. You state that at the beginning of this paragraph, then contradict it at the end. The gear ratio remains constant. The torque ratio remains constant. Only the ratio of power mechanically transferred to the power electrically transferred changes, which is why it is called a Power Split Device.

If you want to say that the virtual gear ratio changes, that's would be okay. You could also correctly say the the gear ratio effectively changes, but does not physically change. You need a qualifier to make the statement correct.

Tom

 

It would be nice if someone can test the two modes (ECO and PWR) by setting cruise control at say 60mph, resetting the mpg and doing 2 passes in each mode to get a FE reading. It is obvious that in both modes full throttle is full throttle, but at cruising speed does it have any effect on FE?
I am too lazy to test this myself.
thanks

 

I think there will be no difference when using the CC at a steady speed, the car uses as much power as it needs to maintain that speed. The only exception might be if you were using the AC, then there could be some small difference because ECO mode operates the AC more efficiently. Some people in other threads have reported differences in CC operation in the different modes, I have not observed this.

The CC doesn't grab the throttle and pull it down like earlier CC systems did, it has it's own input to the ECU which should be uneffected by pedal mapping.

 

This has been covered before, but here it is again in a nutshell:

1) Full power is full power, regardless of the mode.

2) Mode selection has no effect on the basic efficiency of the engine or HSD.

3) ECO mode does reduce the use of air conditioning, and varies the threshold at which the ICE starts to run. In other words, ECO favors mileage at the expense of comfort and snappy driving.

4) Gas pedal response mapping changes between the three non-EV modes. This does not directly effect mileage, but it does make it easier for a lead foot to finesse the pedal.

Tom

 

I see, that makes sense. When CC is set and you travel uphill, the ice response is the same regardless if it is in ECO or PWR mode.
So the absolute only difference is the pedal feel, with the exception of the AC compressor reduced output while in ECO mode.

 

I believe pre-release publicity indicated that CC is less aggressive in maintaining a precise setpoint speed in ECO mode than in Normal. I.e. it tries to get better economy by allowing more variation.

I don't use it enough to know.

 

So then, having cruise set while in pwr mode the prius will try to get back or maintain the set speed more aggressively than the same in ECO mode? Wouldn't that affect FE?

 

Yes if it actually works that way. What fuzzy1 posted was that "pre-release publicity indicated" that it might work that way. Someone needs to test it. It would be a fairly simple test:

Find a level section of road and set the CC at some speed, then cancel it and coast down 10 or 20 MPH and hit resume. Time how long it takes to get back to set speed, repeat for the other modes.

 

OK - I don't know if this is written anywhere, I could not find it.
Understood - you floor the accelerator in ECO/Normal/PWR mode, 0-60mph is the same.
ECO changes the A/C - engine function for cooling/heating.
The modes change the accelerator mapping.

But did anyone notice and write here that in PWR mode the engine does not turn off when gliding and that the display shows instantaneous fuel consumption around 1-2.5L/100km while the Energy monitor is showing arrows going *only* from the battery to the wheels???

If what I saw today is true and the energy monitor does not have a bug, then the engine is left running to the minimum, without letting it turn off, while not giving any energy to the battery. If that is the case, then fuel is wasted to achieve this - or at least it is not shown that the "forced fuel burning idling" is charging the battery as well.

Why would this happen? to make sure that when you press the accelerator you have the ICE ready without any lag to spin it up. I am not saying that it never happens that the engine is off while the battery is pushing the car, but *quite* often the engine is running, according the energy monitor, without pushing the car.

Did anybody notice this? or are you still all convinced that is only the accelerator mapping?
To me the modes change the strategy adopted to provide the energy to the user - this is what I see.

How can you achieve, as users mention here, the same fuel consumption in PWR rather than in ECO or normal, I don't know. Likely they are driving ever so often faster than 50-70km/h, when you can glide using the battery only. If you drive at slower speeds, when you can glide electrically at 0L/100km, the ICE is still on, consuming fuel. Today I got on my standard route 0,5L/100km more than in ECO and traffic conditions and weather/AC were standard compared to driving with ECO.

PWR mode therefore, likely consumes the same at higher highway speeds because at those speeds the ICE needs to be on in any case to push the car. And the extra fuel in other less often situations where you are gliding at slower speeds, is averaged out.

If this is the case, at least there is a bug in the Energy monitor display, since the ICE consumption is not zero and there are no arrows going to the generator or the wheels (via the electric motor, that is).
Could you try it out and let me know?

Again, yes - the 3 modes provide all available power if flooring the accelerator (or let's say in the last quarter of the accelerator run). But in between other things happen. I am also still convinced that the valve timing of the ICE is changed in ECO mode, in comparison with PWR mode. One example? I was driving today in PWR mode on the autobahn at about 150km/h giving x% gas. The engine had a certain noise. I changed to ECO mode, pressed the accelerator by an extra y% to keep acceleration constant (to compensate for the mapping) and the engine was making a more muffled noise. In ECO the engine noise is always muffled, compared to PWR, IMHO. Is like as if for the first half/three quarters of the accelerator run the engine is getting more air than fuel in at the same rpm. Could it be? or something similar?

In the US you cannot likely make this test at high speed as mentioned above, but I tell you, the behaviour even at higher speeds is different. Moreover, in PWR mode I noticed that the HSD tries to keep battery charge levels high to provide the extra kick when pressing the accelerator. This is not the case in ECO mode.

I don't have a Scangauge, so I don't know if anything can be checked to see what happens that can be measured effectively. The accelerator mapping also does not help because to get measurements in different modes, one needs to find 2 different accelerator positions, that yield the same required output from the HSD.

Comments? did anybody notice the above?

 

sorry, but gotta say this.

0-60 mph discussions on a high mileage vehicle; what a waste of time

 

DaveinOlyWA: I don't agree - for 2 reasons.
1) the vehicle in question has 136HP - maybe in the US does not sound like much, for EU is a car with some juice. And it shows at traffic lights. I live in Munich and I have often Porsches, Audis, Mercedes and a lot of heavy accelerator drives in the lane next to me. Moreover the discussion was about whether 0-60 in different modes made any difference (it doesn't)
2) the thread is not about performance, is about what the modes actually do

We all know that 0-60 in 10,4 secs is not a Porsche, but if the 0-60 performance of a high mileage car would be 20 secs, Toyota would sell a whole lot less of them, trust me. In absolute terms, I could *maybe* agree with you. But in relative terms, knowing what a vehicle does in 0-60 tells you a lot in its responsiveness. And a car that does a high mileage but when I kick the accelerator does not move, possibly not taking me out of a difficult situation, it is not something I would be interested to buy. Especially if it has 136HP and not 100 or even less.

 

I agree when you are trying to select a car it's nice to know a little bit about acceleration, 0-60 MPH times at least give you some idea. For those of us who spend a lot of time on 2 lane roads and need to pass other vehicles from time to time knowing the 40 to 80 MPH time might be more useful.

I consider a 0-60 MPH time of 10.5 seconds (Gen3 Prius) to be acceptable but 8 or 9 would be better. Anything longer than 13 or 14 seconds I do not like, although I have owned several that were probably that slow. Slower accelerating vehicles are fine if you spend your driving time around town or on the freeway, but driving on two lane highways I don't want anything that accelerates like a 1959 VW bus.

 

pakitt; thank you for your feedback. sure acceleration is important but;

1) around here;
A) i am rarely first at the light
B) so pressed for time or unprepared that i need to "make up time" while driving

2) what i value MUCH MUCH more is passing ability. so lets talk 45-70 mph times. that is what i use. off the line speed i have used maybe a half dozen times in the 6+ years i have been driving a Prius and only to impress someone else i knew and not to meet my driving needs.

 

I can confirm that pwr maintains speed better. If I have cc on in a hilly section of road I will slow down more in eco mode. PWR mode will slow down but not as much and will speed up faster to get back to the set speed.

Gear ratio from MG1 to wheels is constant. The gear ratio from the engine to the wheels works somewhat like a cvt. Perhaps the ICE gear ratio or some better term is needed. On my previous car there was a transmission rocker switch that had Normal, PWR, and SNOW on it. I would think on the HSD PWR could keep the battery SOC higher and use it when accelerating and pop the ice rpms up quicker. This would not change 0-60 times with full throttle, but would change the engine response.

It would also be nice to be able to set virtual gear ratios that behaved differently when the accelerator is not pushed. On hilly or curvy sections I would like more drag created by the mgs by generating electricity. In normal driving I would like no driver imput to be glide, that is no extra drag or power generation.

 

That would be a nice extra bit of information to have, but...

There is a reasonably high correlation between 0-60 mph times and 45-70 times if you are using optimum available gear ratios in both cases, which the Prius does an admirable job of when you put your foot to the floor.

0-60 mph combined with 0-100 km/hr (which is almost the same) is nearly a universal world wide standard that makes it easy to compare acceleration of cars in the moderately high performance to sluggish range.

 

hmm. ok.

sorry, but if that were the case, we would not need a transmission at all correct?

what does not correlate is when the ICE can provide the most power. available torque is what provides the acceleration. its not the same at all speeds.

and besides, that is not the point i am trying to make here. once again, i dc about something i do not use and why should i??

i dont drive the Prius to show others i am just as stupid as them when it comes to wasting gas for little or no reason and that is exactly what off the line time essentially is.

now, passing speed in many cases really comes down to safety. as tumbleweed mentioned, passing speed is something i use, so yes i care very much about it.

i did not say that one correlates to another, although with the type of ICE a Pri uses, i think it correlates less than a normal car

 

The times necessary to go from speed x to speed y (in brackets speeds in mph) are as follows, as tested by Italian Car Magazine "Quattroruote" in Sept. 2009:

70-100 (43,5-62,1) 5,8s
70-120 (43,5-74,56) 10,6s
70-140 (43,5-87) 16,8s
1km (0,62mi) starting from 70km/h (43,5mph) 28,3s (exit speed 166,1km/h-103,2mph)

BTW - acceleration speed:
0-60 (0-37,28) 5s
0-100 (0-62,14) 11,3s
0-130 (0-80,78) 18,9s
0-160 (0-99,42) 30,6s
400m (0,25mi) from standstill 18s (final speed 127km/h-78,91mph)
1km (0,62mi) from standstill 32,6s (final speed 164,1km/h-102mph)

Because we know now that ECO and PWR mode make no difference when flooring the accelerator, it is irrelevant which mode they used in these tests.

 

How do you get that out of "if you are using optimum available gear ratios" ?

at full throttle in the speed ranges discussed, it's close enough to give a meaningful comparison.

I wasn't suggesting that you did, I was telling you that there is a strong correlation between 0-60 times and 45-70 times. If you choose to ignore widely available useful performance data, feel free to.

Yes, but I did say that.

 

Interesting observation, I did some tests a couple of days ago, which isn't to say your observation is wrong, I think I was looking at a different aspect of the CC/mode question

Level road, no wind, I set the cruise control for 65 MPH, disengaged it and dropped down to 40 MPH. Then from a steady 40 MPH I hit resume and timed how long it took to get to 60 MPH. I didn't time it clear back to it's set speed of 65 because it decreases acceleration starting about 3 MPH from the set speed. I run the test at least 3 times in each mode, ECO, Normal, and Power.

Results were the same in all 3 modes 14 to 15 seconds from 40 to 60 using resume. From that I concluded that the mode has no effect on cruise control operation, at least not when you resume from a 25 MPH lower speed. I didn't do any tests using a smaller speed differential.

It might also be interesting to do a "full power test" over that same speed interval to get an idea how much of the available power the CC is using on resume.

 

The gear ratio from the ICE to wheels is fixed. All of the gear ratios are fixed. The split of torque from the ICE to MG1 vs the ICE to the wheels is fixed. Perhaps you are confusing this with the split of power, which varies depending on the relative speeds of the components. This, of course, is why Toyota refers to the little fixed planetary gear box as a PSD, or Power Split Device.

Tom