I think that you are trying to "prove" something that is buried inside a complex system and that there are far too many variables in your real world to reveal the effect and you have no way to turn this particular parameter on and off to test the effect. I think you will drive yourself crazy trying to control all of the variables (temperature, road surface, altitude, speed, wind, tires, throttle pressure, etc.). I'm sure that Tesla has complex analysis systems that they use to measure and fine tune the motor controls but I don't think they would give you one of these systems so that you could prove that it is working to your satisfaction on your car. I'm perfectly content to let Tesla do the engineering and not make them prove to me that it is working as they say.
I'm not trying to control the variables like temperature and speed. I just try to record them accurately, so I can compare my actual efficiency to what EV Trip Planner predicts. It hasn't been all that difficult, mainly because for most of the trips it means making my wife do it.
As for Tesla's complex analysis systems, as this point I would settle for any indication that they know that torque sleep is actually working properly on my car. I really think that it is possible that all the Tesla engineer did when he pulled the logs was confirm that I had a firmware with torque sleep, and then extract some numbers. I have no evidence of engineering checking to see that torque sleep is functioning at all, much less functioning properly. I'm not trying to get them to give me any system to let me prove anything. I just want confirmation that my car is functioning properly, because the evidence that I have thus far leans strongly in the direction that it is not.
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Perhaps it's not the cold, but rather snow/slush/water on the street. If the AWD system is kicking in to maintain traction, torque sleep isn't going to be able to engage.
We're not driving on snow/slush/sleet/water a large enough percentage of the time for that to account for seeing almost no efficiency gains from torque sleep. The highway clears pretty quickly after it snows. I appreciate the thought, but I really don't think that could be it.
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I've seen the same behavior that LolaCC reports. It's subtle, though: I can't feel it but I can see it happen on the power meter.
I'll definitely try to watch for it on the power meter. Thanks!
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Andy:
I know you desire to make sure that your P85D is functioning correctly vv Torque Sleep. However, since you share seat time with your wife and the weather and conditions are sub optimal in your local, I suggest you wait a month or so to when the weather is better and then see what happens. Till then, just enjoy the car and yourself. Seems to me that you and your wife are able to get back and forth OK even in the cold and snow as it stands now. Were I you, that is what I would do... Drive it like you stole it and smile.
But even if I were to do that, what would that prove? Let's say I suddenly see efficiency improvement from torque sleep when the weather is warmer. Tesla never said "torque sleep doesn't work in the cold." If that is why I'm not seeing an efficiency improvement now, don't you think all Tesla owners and potential owners should know this about torque sleep? The winter is when we most need efficiency gains and every little bit of range, because when it is cold is when range suffers. If it turns out that torque sleep just doesn't work at all when it is cold, I really would like to find that out.
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I already have too many indicators nattering at me. I really don't want to have another blinking light distracting me and tempting me to "game" it. I'd much rather just drive the car. I trust Tesla to optimize the performance of the car and leave me to just drive.
Information is power. You can choose to ignore the information if you want to, but if you don't have access to the information you are operating in the dark. I'd love to have some sort of indication as to which, if either, engine is torque sleeping.
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I think it's very challenging to do this at a microscopic level. However, at a macroscopic, we should all see, since the availability of the new firmware supporting Torque Sleep, a "general improvement" in power usage (Wh/mi) or range (miles) - of about 5-10% (I think that's the number communicated).
I can't definitely say that I'm seeing such improvement (everything else being roughly equal in terms of driving, temperature, etc), but I do see people who are reporting it, so there is a legitimate question as to whether there is something wrong with some cars.
I wouldn't try to control all variables: just look at a long term average. There should be some visible improvement (5-10% is visible/noticeable)
-- Greg
Well, in addition to the trip data I'm collecting, I did include some long-term data. It doesn't show anything close to a 5-10% improvement. As I explained in my initial post, it shows an improvement of 14 wh/mi. 14/416 = 3%. But as I explained, that is certainly an inflated figure, because of the reasons I stated earlier, those being:
1) New tires for about half of the original period being measured
2) Range mode never used in original period and then used extensively in subsequent period
3) Far more 0-60 launches done in initial period
I actually think almost all of the 3% can be attributed to the things above.
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I'm finding it hard to imagine why some people think there is something wrong with their special car. Torque sleep is entirely implemented in software and if you have the software, it will work the same in all cars. If you have the software, it is working. What would be special about some cars where the software would not work?
I just edited myself before hitting "post", which was probably wise, as I might have had my first ever post moderated away to snippiness or someplace. But I really can't believe you posted that.
Yes, every Tesla ever made and every part in every Model S ever made has always worked flawlessly forever. There was never a part anywhere, ever, that malfunctioned, or had been manufactured with a small defect. There was never a bug in a firmware version that could have an affect on some cars but not others. None of those things are remotely possible. I'm not sure what I was thinking.
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I don't have a P85D - just a lowly P85 - but I recently made two identical trips on two different days, and look at the results...
Two days ago I drove 70 miles or so. It was in the low 60s where I live. I drove 70-75 MPH on the freeway. My average energy consumption for that trip, according to the "Since Last Charge" screen, was around 310 Wh/mi.
Today I made the same trip. It was in the mid 70s. I drove 65 MPH on the freeway. My average energy consumption for this last trip - an identical route - was 266 Wh/mi.
That's a difference of about 15% within two days, on the same exact route.
I'm not sure what your point is, or how that applies to this discussion. I'm fully aware that efficiency varies greatly with temperature. If you take a close look at the numbers I included, you'll see huge variations in some of the same trips (taken on different days.) But I'm plugging the temperatures in to EV Trip planner, and then comparing my numbers to what EV Trip Planner predicts. EV Trip Planner also accounts for the temperature.
Taking temperature into account, I am consistently seeing efficiency worse than EV Trip planner predicts. Taking temperature into account, and IN THE COLD other P85D owners are seeing efficiency 8-12 % BETTER than what EV Trip Planner would predict.
That is one of the main reasons I think something may be amiss with the way torque sleep is functioning in my car.