Stop the Press! Tesla announces REAL HP numbers for P85D and P90L

[Stoneymonster]

Whoa. Hard to believe this is still going. I'll check back close to the heat death of the universe.

 

[brianman]

Conjecture is that it is simpler for Tesla to manufacture the packs with one kind of fuse and contactor than with two different types, and that the incremental cost of the better fuses and contactors is not that significant.

Not just to manufacture, but to manage when dealing with maintenance and replacements.

Pack types they have to manage so far for Model S:
1. 60 kWh (limited to 40 kWh)
2. 60 kWh
3. 70 kWh dual
4. 85 kWh A
5. 85 kWh B+
6. 85 kWh dual
7. 90 kWh single
8. 90 kWh dual
9. 90 kWh dual ludicrous

As I understand it, Service isn't allowed to replace your battery with a battery from a different bucket above without negotiating with the customer first.

With Ludicrous upgrade, they now have an additional type:
10. 85 kWh dual ludicrous

One would hope they start killing off production of new packs of types 1, 2, 4, 6, and 8 -- giving users (software limited if necessary) improved hardware if warranty replacement is required. Making Ludicrous "standard" for dual-capable packs seems totally reasonable if they want to simplify as I've described.

 

[tomas]

We interpret differently. My impression is that the majority of "upset by Tesla on this issue" folks fit into neither of those buckets. In contrast, I see a lot of those "seeing Tesla as not having done wrong here" seem to want to put "the upset" into those two buckets for some reason. I guess it's a "cognitive simplicity" thing or something or just rudeness; I'm not sure which.

You really should have stopped at the second sentence, I'd agree completely. In the third, you fell into exactly the same generalization: characterizing "a lot" of a group of members as wanting to oversimplify... then, of course, calling them rude, or maybe stupid.

There are a lot of good and useful posts in here... I wish there were less mudslinging.

 

[brianman]

My question - for the owners that feel taken advantage of and upset, would you feel satisfied if Tesla refunded your purchase amount in exchange for your vehicle back and the inability to purchase Tesla vehicles in the future? I'd honestly like to know if this is the outcome some are seeking.

I don't think anybody is seeking this, as it's bad for Tesla, the customer, and the mission.

 

[tomas]

Whoa. Hard to believe this is still going. I'll check back close to the heat death of the universe.

I think that occurs when a P85DLMP hits whatever instant kW reading generates 691 HP (less traditional drivetrain loss).

 

[brianman]

customers that intend to harm me.

You're painting a lot of people incorrectly here.

 

[lolachampcar]

Sorry to have to repeat.

"Does the 691 combined motor hp worth of extra low end torque help? Yes. Does its contribution come anywhere near close to that of the extra two driven wheels or the increase in battery power limit. No."

If anyone doubts this, do the simple thought exercise of putting Tesla's 691 motor hp in the rear motor only car with a PxxDL capable battery. The car will be marginally faster to 60 mph. That increase will be solely from the extra torque available from the time the car is not traction limited until the time it gets to 60 mph.

To say it is only the torque that drives the performance increase is simply wrong. It is how that torque has a chance to get to the ground. Once the battery source limit is reached, the extra torque provided by the 691 motor hp evaporates.

I'm in agreement with the idea that the extra torque provided by 691 motor hp is advantageous; It simply is not controlling. So why advertise a product based on an advantageous element which is not controlling? This is especially curious when that extra torque advantage disappears when you hit the battery limit.




Reading over the post to check for spelling/grammar errors and my mind wandered to a P85+ (two wheel drive) that actually had 691 horsepower. The traction limit would likely have gone all the way through 60 mph. It would also be one very fast car if not so quick as the P85D. It is these kinds of comparisons that make me really regret the use of 691 hp in pitching the P85D.

 

[stopcrazypp]

Sorry to have to repeat.

"Does the 691 combined motor hp worth of extra low end torque help? Yes. Does its contribution come anywhere near close to that of the extra two driven wheels or the increase in battery power limit. No."

If anyone doubts this, do the simple thought exercise of putting Tesla's 691 motor hp in the rear motor only car with a PxxDL capable battery. The car will be marginally faster to 60 mph. That increase will be solely from the extra torque available from the time the car is not traction limited until the time it gets to 60 mph.

To say it is only the torque that drives the performance increase is simply wrong. It is how that torque has a chance to get to the ground. Once the battery source limit is reached, the extra torque provided by the 691 motor hp evaporates.

I'm in agreement with the idea that the extra torque provided by 691 motor hp is advantageous; It simply is not controlling. So why advertise a product based on an advantageous element which is not controlling? This is especially curious when that extra torque advantage disappears when you hit the battery limit.

Vg's graph did not account for traction limit (this would show up early in the torque graph), but even accounting for traction limit, the contribution from the extra torque seems to be far higher than the tiny bit of increase in power. When I get home, I can probably do a graph that does factor in traction limit (from torque graphs from sorka which shows the torque ramp).

Basically the 691hp motor power P85D has all the A+B+C regions in the torque graph minus losses from traction vs a 463hp motor power P85D that would only have the C region which is a tiny sliver.

 

[LetsGoFast]

They have. Half price L upgrade for a period. I'm sure someone will sneer, but I'm pretty sure it was offered because of this noise. I predict that's it, because (as I've posted before, but stuff gets buried here quickly) anything more would likely be construed as an admission of guilt, and would invite sharks to swim rapidly to the blood.

Perhaps you are right. I'm very pleased that Tesla have offered the ludicrous upgrade at a reasonable price and will be even more pleased if they ever actually let me have it! I've not counted noses, but I think most of us that are dissapointed by Tesla's handling of the 691 affair have expressed praise for the upgrade path. I'm not certain that it is being offered because of the HP issue as much as due to the ever-present carping by those who are unhappy when the next thing comes out and they don't have a path to obtain it. I suspect at some point in the future it won't be a seperate line item -- it will just come with whatever the performance model is. The distinction between insane and ludicrous doesn't really make sense as a long-term strategy.

 

[Jian Yang]

I really wish this straw man would stop coming up. To my knowledge, nobody on TMC has expressed the expectation of "691 hp on the wheel".

In contrast, there was an expectation of an "after losses" number at least coming close to "691 power at the motors" -- which apparently is "completely different" from "691 hp motor power" and only idiots or people that "didn't do due diligence" didn't understand instantly. /rolleyes

You are quoting me out of context.

 

[Laserbrain]

The number was not inflated, it is a true number that represents some aspects of car performance. It is unfortunate that what the number represents was misunderstood by some customers.

Of course the number was inflated. Or do you think a Tesla S with real 691 hp (not limited by a battery) would have had the same performance as the actual Tesla S with 691 fake hp? Get real. The number did represent a scientific value, there was nothing to misunderstand.

They don't do that because ICE car horsepower has always described power of the ICE itself, not the fuel. But they have done (and continue to do) something similar to Tesla, which is to use non-factory equipment during testing of the engine/motor.

So the ICE manufacturers use racing gasoline, an added turbo charger and maybe a NOx injection to determine the hp - some fake hp - of their cars (which in real life use normal gasoline, no turbo charger, and no NOx injection)? That would be new to me. But then, looking at the criminal energy of Volkswagen, everything is thinkable these days.

The problem isn't that they "have nothing to do with each other" it is that "motor power" is only relevant to imply torque. There is no particular reason to represent torque obliquely through the use of "motor power" -- Tesla could simply have said they produce 686 lb/ft of torque compared to 443 for the P85. This would have perfectly described the reason for the prodigious low end acceleration without providing misleading information about the engine's power. It was particularly disingenuous given that it was already commonplace to specify horsepower either at the motor shaft or at the wheels and it had to be clear that most reasonable people would have assumed that 691 hp "motor power" was attempting to say 691 hp at the motor shaft, not 691 hp in some hypothetical application not in any actual car being sold.

+1

Who cares about torque? Tesla did not advertise false torque numbers. At least not that I am aware of. They advertised false 691 hp numbers. Now they are advertising the correct 469 hp numbers. Everything is good again. Case closed.

 

[brianman]

Here's the problem. Once the mistake was made,,there's no way back. None. Any voluntary admission of culpability or compensatory offer is an admission of guilt that invites suits, etc. and would significantly impact mission. so, those long term supporters need to decide how many mistakes they allow tesla before abandoning them.

Here we disagree. If you can't trust the people spearheading the mission, then the mission suffers. Honesty and willingness to admit mistakes in general strengthens the mission and the people driving it.

 

[brianman]

calling them rude, or maybe stupid.

I didn't call them rude or stupid. I suggested that the behavior was rude and that the approach was oversimplifying. Describing behavior is different from describing people.

- - - Updated - - -

characterizing "a lot" of a group of members

I should have been clearer here. I was referring to "a lot of posts" rather than "a lot of posters". It's the posts themselves, not the posters I was referring to. Apologies for the vagueness in my original phrasing.

- - - Updated - - -

People will never get 691 hp on the wheel, period, so stop hoping for it. Tesla never offered 691 hp on the wheel, they offered 691 hp motor power. People complained about not getting something they mistakenly thought they were offered. IMO, P85D buyers and tesla are both responsible for this misunderstanding. Tesla is trying to provide the P85D performance improvement (which was not guaranteed), just like all other free OTA improvements. Tesla is actually trying to do something good here and this kind gesture does not mean they were guilty. So be at peace and enjoy.

I really wish this straw man would stop coming up. To my knowledge, nobody on TMC has expressed the expectation of "691 hp on the wheel".

In contrast, there was an expectation of an "after losses" number at least coming close to "691 power at the motors" -- which apparently is "completely different" from "691 hp motor power" and only idiots or people that "didn't do due diligence" didn't understand instantly. /rolleyes

You are quoting me out of context.

I'm confused. What context was lost by omitting the italics above?

 

[lolachampcar]

Vg's graph did not account for traction limit (this would show up early in the torque graph), but even accounting for traction limit, the contribution from the extra torque seems to be far higher than the tiny bit of increase in power. When I get home, I can probably do a graph that does factor in traction limit (from torque graphs from sorka which shows the torque ramp).

Basically the 691hp motor power P85D has all the A+B+C regions in the torque graph minus losses from traction vs a 463hp motor power P85D that would only have the C region which is a tiny sliver.

stopcrazy,
There is no doubt the extra torque helps. My problem is going through the mental gymnastics trying to "prove" that using 691 combined motor hp to extract the increase in torque that the 691 combined motor horsepower represents is what makes the P85D so quick. Somehow this justifies or makes valid the 691 combined motor hp way of describing the car.

See
See
It is the extra torque that makes the car quick. That extra torque came from the 691 combined motor horsepower so that is the correct way to describe the car.

This logic has some merit but completely neglects the added two wheel drive and increased battery power contributions to the P85D being quick and, more importantly, completely ignores the battery power limit making the whole more torque from 691 combined motor power useless once the battery power limit is reached.

I'm beginning to sound like a broken record. I'm getting tired of listening to myself thus others have really got to be tired of reading my posts. Time to move on.

 

[vgrinshpun]

Vg's graph did not account for traction limit (this would show up early in the torque graph), but even accounting for traction limit, the contribution from the extra torque seems to be far higher than the tiny bit of increase in power. When I get home, I can probably do a graph that does factor in traction limit (from torque graphs from sorka which shows the torque ramp).

Basically the 691hp motor power P85D has all the A+B+C regions in the torque graph minus losses from traction vs a 463hp motor power P85D that would only have the C region which is a tiny sliver.

I would not use Sorka's graphs to properly account for traction limit as the professional testing done by Consumer Reports produced vastly different result - it showed P85D traction limited only for the first 1/3 of a second, while able to put all torque available from motors up to the speed (30mph) at which torque and power become battery limited.

 

[Canuck]

Here we disagree. If you can't trust the people spearheading the mission, then the mission suffers. Honesty and willingness to admit mistakes in general strengthens the mission and the people driving it.

That's nice in theory but in reality the opposite is true. Microsoft, Apple, Facebook, Google, Exxon, GE, Wal-Mart, etc., etc., didn't get to where they are based on honesty and admission of mistakes. It's a dog eat dog world and only the strong survive. In big business admission of a mistake is an admission of weakness and honesty isn't always the best policy. Capitalism is like evolution: a cruel and brutal process. Tesla's is likely following the standard legal advice to never admit a mistake but do damage control -- which is similar to how evolution deals with a flaw. The mission to make Tesla a big business like these so the most people possible will be driving an EV. It's not to be "Mr. Nice Guy" and perish.

 

[redox]

Microsoft, Apple, Facebook, Google, Exxon, GE, Wal-Mart, etc., etc., didn't get to where they are based on honesty and admission of mistakes.

Somehow googling "Apple admits" brings in a lot of results. Replacing "Apple" with the other names is left as an exercise to the reader (hint: more results of admission of mistakes come).

 

[Auzie]

Somehow googling "Apple admits" brings in a lot of results. Replacing "Apple" with the other names is left as an exercise to the reader (hint: more results of admission of mistakes come).

Interesting. I followed your advice and googled 'Tesla admits'

Here is what comes out

:biggrin:

 

[yak-55]

I’ve put together few charts that illustrate the point that I’ve been making for some time: that the improvement in 0-60mph acceleration that Tesla was able to achieve in P85D vs P85/85D (0.8 sec), in spite of the power limitation imposed by the battery, is mostly due to the increased combined torque available from the two motors with more that 50% increased power rating (686lb-ft in P85D vs. 443 lb-ft in P85).

First, few basics. As I mentioned before, based on the Second Newtown Law, acceleration is defined by the applied force. As applied to the rotational motion, the acceleration *time* is defined by the applied torque and is proportional to total connected inertia and reciprocal to the accelerating torque (the difference between the torque of the motor and the load torque). For those interested in more details, they are available from the “Calculating Motor Start Time” on-line course. The pertinent formula illustrating the above statement is included below.



As I’ve mentioned many times before, based on the above, the accurate estimate of acceleration can be performed only by analyzing the torque and power curves, not by comparing a single point from these curves across technologically different drivetrains which yield very different torque and power curves.

Here is how the idea of acceleration being accurately ascertained using the torque curve was expressed by the former Mazda Engineer that worked on Miata Project in his book (Norman H.Garrett III, Mazda Miata Performance Handbook):

View attachment 102730

So, I started with building the power curves for the P85 and P85D, based on description that I’ve provided here. The curves are based on current specification of the P85D (728hp), because I did not have access to the rpm values that correspond to the older (691hp) specification. The curves are idealized, i.e. do not take into account transients and decrease in power output of the motors at higher speeds, as I do not have the necessary data to accurately represent these effects.

The combined power curves for P85 and P85D are shown using shading – the green area outlines P85 curve, while green plus yellow area outline the P85D power curve. There are two charts – one using rpm on the horizontal axis, another – mph. The mph are calculated based on 9.73:1 ratio (common for both front and rear motors per the Model S Manual) and based on the tirerack data for the 245/35R21 Continental DW summer tires (750 revolutions per mile).

View attachment 102731

View attachment 102732

The torque curves are built based on the power curves, taking into account that the drivetrain outputs rated torque (horizontal portion of the torque curve) up to the speed at which it reaches its power limit. After this inflection point the torque declines with the increase of rotational speed (rpm) so that power limit is not exceeded. The torque curves are built neglecting the transients and the fact that the power limitation imposed by the battery is not a horizontal line, but a line that is sloping down with the increase in rpm.

View attachment 102733

View attachment 102734


As seen from the attached charts, the increase of the area under the torque curves from 0-60mph (which is proportional to power) can be divided into three areas. Area A represents improvement in acceleration due to the increased combined torque of P85D over the P85 (686lb-ft vs.443lb-ft). Area B represents improvement due to the increase in power limit of the battery from 416hp to 463hp. Area C represents improvement in acceleration due to both motor torque and battery limit improvements.

I will do actual calculations next week, but as can be seen from the graphical presentation, splitting area C in half, with each half allocated to the improved acceleration due to torque and horsepower improvement, it is clear that (0-60mph) acceleration improvement due to the increase in combined rating of the drivetrain motors dwarfs improvement due to increased power from the battery. Just eye balling it for now, I would say that 85-90% is due to the increased drivetrain motors, while 10-15% is due to increase in battery power.

In summary, your conclusions are not consistent with the data and are simply wrong.

The analysis of these curves, as I alluded before, leads to several additional implications, including the one that I repeatedly referred to by saying that square peg does not fit into the round hole, and I am sure that the lively discussion on this topic (as it is central to the assertion made in the unhappy owner’s letter) is next…

This is all an interesting diversion ... and gets us to the same place. More torque, traction (4WD) and excellent traction control (high bandwdith motor controls) are consistent with the delightful 0-60 performance of the car.

The *misleading* part of the 691hp claims does not involve low speed (certainly below the traction limited regime of 0 to about 30, or even the torque constrained region below max battery power at about 40 mph). This performance dominates the 0-60 result (and is awe inspiring) ... but the issue of NEVER delivering more than 463hp STARTS at 40 mph, and is profoundly noticeable above 70mph. Somehow were arguing about the end of the speed range where we all agree Tesla has accurately (with its 0-60 numbers, at least with the roll out clarification) described the vehicle. This is a full diversion from the high speed performance gap implied by the high hp claims that is (at least for me) the real failure to deliver. This car would run like a scalded cat up to well over 100 mph if it REALLY had close to 700 hp. It doesn't. They said (clearly) it did. This is the issue.

 

[Canuck]

Somehow googling "Apple admits" brings in a lot of results. Replacing "Apple" with the other names is left as an exercise to the reader (hint: more results of admission of mistakes come).

Sorry, I stand corrected. You are right. Microsoft, Apple, Facebook, Google, Exxon, GE, Wal-Mart, etc., etc., are honest and readily admit their mistakes.

But just as an aside, did you read those articles? For instance, here's probably the worst thing Apple has admitted to:

Apple admits using child labour - Telegraph

"Apple said the child workers are now no longer being used, or are no longer underage. "In each of the three facilities, we required a review of all employment records for the year as well as a complete analysis of the hiring process to clarify how underage people had been able to gain employment," Apple said, in an annual report on its suppliers.

Thanks for showing me that honest admission from your "Google" search. And here I am thinking what Apple was doing was not an admission at all, but "damage control" which is what I said in my post that big corporations do. Wait, that quote from Apple was from 2010 and it said "child workers were now longer being used." I better end my search there and not read this article from 2012:

Your iPhone Was Built, In Part, By 13 Year-Olds Working 16 Hours A Day For 70 Cents An Hour* - Business Insider

Oh well, that's only child labour so it's nothing to be concerned about, right? Apple is honest and admits it's mistakes. For instance, when Apple makes a defective product, they are honest and admit it, right? Your search results showed me that. But, darn me, I had to go and actually read past the headlines....

"It’s taken 6,000 pissed-off customers, a Change.org petition, and an entire website named Staingate, but Apple has finally agreed that yes, a coating peeling off Retina Macbook displays is not good."

Apple Admits That Delaminating Screens Might Actually Be a Problem

Yes! There's honesty and not damage control for you!

Now, let's see what Tesla says on the issue that is the subject of this thread:

"The Tesla spokeswoman concluded: “Customer satisfaction is of the utmost importance to Tesla. In the rare case when a customer finds their Model S isn’t for them, we’ll do what we can to help them move on.” "

http://www.carbuyer.co.uk/news/151308/watchd

Damn, no admission. Tesla can learn a lot from the honesty and admission of mistakes from Apple.

I was going to go on with Exxon, because you told me you left the other searches to me and even gave me a "hint: more results of admission of mistakes come" but my sarcasm is wearing thin. I don't think I could handle Exxon's admissions and honesty. I will also leave that to the readers. I trust they will read the articles rather than the headlines.

But your Google search tool was fancy.