If nothing else, the REST API is the best thing we have for relative comparison. Otherwise you are pixel peeping at a display not intended to be read precisely. Comparing before/after firmware changes (at the same SOC!) on the REST API gives us definitive answers about percent differences, even if not the absolute number.
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[updated with *] P85D 691HP should have an asterisk * next to it.. "Up to 691HP"
- Thread starter krisg81
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- Driving Dynamics Model S
Yea, to be a valid comparison, you have to compare .153 to .168 which has the same font change. Wish I had a picture from yesterday so I could show the difference on the same graphic. Maybe someone with 153 who hasn't gotten the update can try this and post a picture.
But as you point out the "about the same place between the lines" comment, it actually isn't. The ratio is not the same in the two pictures even if the font is a different size.
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Hmmm... you could be right. Looks like they shrunk the font of the kW scale and moved it over so the 160 mph marker fit.
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I've still got .153 (btw where's my 168!) If I remember to give it a try tomorrow I will post a screenshot.
thegruf
Active Member
seems fair, and good to hear that Tesla looked after you.
I don't think it unreasonable to ask these questions of Tesla, so long as they are asked in a reasonable manner.
If the responses are not forthcoming or unacceptable, then it is for the user to challenge it further if they wish to do so.
Actually complaining incessantly on a forum when you haven't even asked for comment from Tesla very much seems to me to be the wrong way to go about things.
Bring on April 30th
I should just about be able to switch my 85D order for a P85D if there is a significant update April 30th
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More accurate maybe would be to compare the "needle" position to the two faint tick marks between the main numbers on the scale, these are possibly at 320/400KW.
Photos above not clear enough to show this.
I agree that if the car is consuming 410 KW that the motor is outputting 550hp at most in situ. Nonetheless, it has nothing to do with the actual hp rating of the motor -- that is completely independant of the amount of power applied to the motor or the amount of energy output in a particular application. Perhaps they will continue to tweak the firmware to apply more power to the engines and change the performance of the car -- but unless they change the hardware, the horsepower rating of the motor will not change.
mnx
2018 M3P
I kind of wonder if the P85D will ever output 691hp, as it appears they just summed up the front and rear motors to get that number. Aren't they geared differently and therefore would have different power curves? I somehow doubt that would account for the theoretical 150hp deficit that we have seen so far.
Is it possible to run the P85D on a 2 wheel dyno and get 2 sets of curves one for the front motor and one for the rear? That way we would know if the front motor and rear motors are putting out their claimed #'s.
Is it possible to run the P85D on a 2 wheel dyno and get 2 sets of curves one for the front motor and one for the rear? That way we would know if the front motor and rear motors are putting out their claimed #'s.
Danal
electricmotorglider.com
And what, in your opinion, determines the HP rating for an electric motor?
The "motor" itself does not, because continuous power rating is one of the primary trade-offs in designing electric power systems. A brushless electric motor, all other things being equal, and particularly the power source (battery, inverter/controller, wiring) being capable, will simply draw more current when it experiences more load. It will continue to draw more current right up to the moment it burns up. Therefore, "maximum horsepower" rating for an electric motor is highly dependent on cooling. Furthermore, transient HP numbers can be quite a bit higher, if by "transient" we mean "3 seconds". And by "Quite a bit", I mean easily double.*
Tesla publishes a 691HP (515kW) number. Do we assume this applies to the entire power system, including cooling? Even assuming that, is 515kW motor input? Output? Momentary? If Momentary, how many seconds? Continuous?
Therefore, the statement "unless they change the hardware, the horsepower rating of the motor will not change" is not entirely true. For example, if Tesla sees from logs on thousands of vehicles that they were too conservative in setting limitations based on cooling, they could indeed change the rating. I'm not saying that it is likely that they will... I'm saying we don't have enough information on where the 'rating' comes from to state that it is an absolute limitation of the hardware.
All of this is VERY unlike ICE motors. Unless an ICE's hardware is changed, there is an absolute peak point of RPM*Torque = Power at Wide Open Throttle on a Standard Atmosphere day. Not so for an electric. RPM*Torque depends on both supplied voltage and experienced load; surviving that depends on adequate cooling.
Well that's not even remotely true for some ICE setups. In some ICE setups, boost on turbo cars is controlled by the ECU and can be increased through software. Yes, some older cars had mechanical wastegate control, but most newer cars control it electronically and it can be increased via software. Some cars can have hp increased dramatically with a software change. Increasing boost usually goes along with increasing air fuel ratio to prevent the engine from blowing up. You sacrifice some economy and longevity which is why the power isn't as high as it can be from the factory.
The other way power can be increased in ICE setups is modifying the lift and duration on cam setups that have software controlled continuously variable cam timing. Again, power can be increased with a software update. Again, this comes with a cost in longevity and additional stress on the entire drivetrain.
stopcrazypp
Well-Known Member
The order page is pretty unambiguous. That rating is the sum of the peak power of the two individual motors: 221 hp front, 470 hp rear. Like all of Tesla's ratings, they are never continuous. While there is no set standard for the exact amount of time for the rating, typically it is on the order of 30 seconds to a 1 minute. The rating will be determined by the nameplate voltage, peak current (for the given time limit mentioned above), and peak rpm (back EMF factored in). Assumption tends to be full load (as that lets you achieve highest number).
It is pretty clear this rating has no regard to the upstream power system (batteries and inverters). The "470hp" motor rating is the same exact motor as the one that was in the P85+ which was rated at 416hp for the car as a whole.
The unique part of the dual motor is that it's entirely possible for the motors to generate 221 hp and 470 hp respectively in the real world (which it might be doing already), but for the car as a *whole* to never make 691 hp because it doesn't do it at the same time for both motors.
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Since the forum seems to think I have sent to many reputation points your way I would just like to say that your endless testing and documentation of said testing is much appreciated! :love:
Tesla should pay you for all the test-data you provide them with
mnx
2018 M3P
These are exactly my feelings, too. I’m willing to give Tesla some time to come up with an update, but I bought my P85D under the assumption that I could trust the marketing numbers. Currently, it delivers mind-blowing performance 0-100 km/h, but only good performance after that. I actually do not care very much about rocket-like starts, but I care a lot about performance at higher speeds (I’m German, so no surprise there). If Tesla does not change the car’s performance at speeds between 100-200 km/h, I’m going to be a very disappointed P85D owner, wondering why I wasted so much money and didn’t just get one of the cheaper variants.
So here's the fully maxed out kW meter under .153... Looks like it's making ever so slightly less power than in .168 (see p. 60 in thread for comparables), as you can't see any of piece of the zero to the right of the orange line below... That assumes of course that no one tweaked the axis labels by a couple pixels between these builds.
Hmm. So that's what I was seeing with 153 as well, however, just to be thorough, I remember seeing several youtube videos where the power start to taper off right around 93 to 94 mph. Is your need in exactly the same place below that? Say at 70 or 80?
And no, it's not the placement of the numbers. In my picture, you can clearly see that its closer to the sub darker color tick.
And no, it's not the placement of the numbers. In my picture, you can clearly see that its closer to the sub darker color tick.
Danal
electricmotorglider.com
You are absolutely correct. I should have specified "normally aspirated, with mechanical cams".
My point still stands: For many decades you can put an ICE motor on a Dyno, run the RPM range, find the peak, and that is the number. Yes, if you change boost, yes, if you change air/fuel, yes.... yes... yes... it moves the peak. There is still a peak, and that is the new number with the adjusted setup.
This is not even remotely true for an electric motor. Put it on a Dyno, increase the load, and the power will increase (as the RPM decreases). This will continue right up to the moment it burns up. So, what is "the" number? For an electric, it will always be conditional.
mnx
2018 M3P
I would think you could just change the gears in the car for the hp peak to be higher raising your 0-60 time while gaining acceleration at higher speeds.
ERP
Ludicrous Member
^ That's not going to work with a single speed. You could install a shorter gear and improve acceleration but lower the top speed. Or install a longer gear with the opposite effect. Being in the US it is tempting to install a shorter gear and lower the top speed from 155 to 125 mph while maintaining the same max motor rpms. But if I was in Germany I would not want to sacrifice the top speed.
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