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P85D and P90D horsepower disagreement

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What about the more important 1/4 time and 20% faster to 155 mph?
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I did not ask, however, based on the tone of the conversation my guess is that the 1/4 time will also be 20% faster. His answer was a clear "no" when I ask if there would by any difference between the P90D and P85D 2.8 second times. I specifically ask if it would be even a 1/10th of a second slower - answer: "no difference".
 

sorka

Well-Known Member
Feb 28, 2015
9,866
8,041
Merced, CA
Except that Tesla never promised you specific performance above 60 MPH. Tesla promised you specific performance from 0-60 MPH. Nothing more, nothing less. You cannot hold Tesla responsible for an expectation that you created, but which they did not set.

No but they did promise a car that has 1 hp for every 7 lbs. The P85D only has 1 hp for every 9 lbs and only performs like a car that has that. It does not perform like any other ICE that has a power to weight ratio of 1 hp for every 7 lbs. Not only that, if it actually produced the power they sold us, it would be faster than every other car that has the same power to weight ratio as ICE cars only make their speced power at one RPM while electric motors make their peak power at nearly all RPMs (within reason).

- - - Updated - - -

That exactly matches what I have just heard from senior UK Tesla folks... EXCEPT that we have been told the "P85DL" makes 0-60 in 2.9s, not 2.8s.

Do you mean 0-62 MPH?
 

sorka

Well-Known Member
Feb 28, 2015
9,866
8,041
Merced, CA
Wow. Two in a row. I didn't think this was being debated anymore. We all know it from the dynos, from the REST data collected, from the performance monitor data collected by multiple members showing the same thing on a variety of metrics.

p85d65P.jpg


And up until today, Tesla has been dead silent about this issue. Now we know that a software update won't provide the hp we paid for.
 
Now we know that a software update won't provide the hp we paid for.

I don't know what you think that graph proves, but I don't see it corroborating what you've said. I would imagine that it's painfully obvious that at different velocities, you can expect different power output from the motor. That's the case for ICE vehicles as well, except replace linear velocity for RPM. If you were expecting a linear acceleration from 0 to 155, or even from 0 to 60, then you were sadly, hilariously mistaken. That's not in the realm of possibility.
 

sorka

Well-Known Member
Feb 28, 2015
9,866
8,041
Merced, CA
I don't know what you think that graph proves, but I don't see it corroborating what you've said. I would imagine that it's painfully obvious that at different velocities, you can expect different power output from the motor. That's the case for ICE vehicles as well, except replace linear velocity for RPM. If you were expecting a linear acceleration from 0 to 155, or even from 0 to 60, then you were sadly, hilariously mistaken. That's not in the realm of possibility.

I thought you were joking before. You're clearly not. You need to go do some research on what has already been done and posted elsewhere before you continue. You're looking foolish.
 
I thought you were joking before. You're clearly not. You need to go do some research on what has already been done and posted elsewhere before you continue. You're looking foolish.

Perhaps you could brush up on your physics before you put your foot deeper in your mouth. The amount of energy required to attain a particular speed increases exponentially, not linearly. This is the case for any engine, electric or otherwise.

Here's a real-world example with three different vehicles:

image005.323212950_std.jpg


Similarly, and as a function thereof, acceleration decreases as time goes on. Another example:

g3-9.jpg


Non-Tesla vehicles deal with the problem of tapering acceleration by offering various gears. Tesla opted not to have a transmission, and to therefore operate on a single "gear". This means that the acceleration (and therefore the "power" you think you feel) is going to be a tapering function of the time you've held the pedal to the floor.

Tesla, as is the case with any other manufacturer, is going to advertise the peak power output of the motor. That also doesn't take into account the loss in efficiency in transmitting that power to the wheels, but that's another story. You got the HP you paid for. You wanted it to be constant for the entire range of the car. Too damn bad.
 

sorka

Well-Known Member
Feb 28, 2015
9,866
8,041
Merced, CA
Perhaps you could brush up on your physics before you put your foot deeper in your mouth. The amount of energy required to attain a particular speed increases exponentially, not linearly. This is the case for any engine, electric or otherwise.

Here's a real-world example with three different vehicles:

View attachment 87746

Similarly, and as a function thereof, acceleration decreases as time goes on. Another example:

View attachment 87747

Non-Tesla vehicles deal with the problem of tapering acceleration by offering various gears. Tesla opted not to have a transmission, and to therefore operate on a single "gear". This means that the acceleration (and therefore the "power" you think you feel) is going to be a tapering function of the time you've held the pedal to the floor.

Tesla, as is the case with any other manufacturer, is going to advertise the peak power output of the motor. That also doesn't take into account the loss in efficiency in transmitting that power to the wheels, but that's another story. You got the HP you paid for. You wanted it to be constant for the entire range of the car. Too damn bad.

None ICE vehicles offer gearing because they produce hp at one peak and they need gears to hold end of the drivetrain as tightly as possible around the RPM that produces the most power. A change in speed is determined by how much power your put down under the curve integrated over time. Ice Cars have to have transmissions with gears. Would the MS benefit from another gear? Probably. It certainly wouldn't benefit from 6, 7, or 8. The DU does become less efficient at higher RPMs due to feedback but it's very very low at typical highway speeds. At 60 MPH, the P85D is only losing 10% from the battery all the way to the wheels. Most ICE cars lose 15% from the motor shaft to the wheels alone. AWD drive vehicles ,because they have to go through many more drivetrain components, often lose 20 to 25%. Remember, the highest output ever recorded on a P85D is 414KW. That's 555 HP in a perfect ideal world with zero losses.

You're graph has nothing to do with this issue and is completely out of left field.
 

eloder

Active Member
Mar 12, 2015
1,214
1,427
Ohio, USA
They did inform me that the car had 691 hp. So off course I expect the car to perform like it has 691hp also above 60 mph.

The P90D is 20% faster to 155 mph, so that is closer to a 600hp car.

691 hp ICE cars don't have anywhere close to the performance you do under 60 mph. An ICE buyer could make the same exact complaint that their 691 hp car only performs as well as a 400 hp Tesla under 60 mph.

And up until today, Tesla has been dead silent about this issue. Now we know that a software update won't provide the hp we paid for.


As noted elsewhere, there's a number of situations where ICE cars (most of their time spent accelerating) where they do not reach rated horsepower.

I don't own a Tesla, but I always find it mind-boggling that people can make a $130k purchase without researching the aspects they care about (i.e., well-documented 60-120 mph times). Especially with new tech like an EV. For example, my own Leaf has a similar 0-60 time as my gas smart car, but you'd find a hard time finding anyone who says smart cars accelerate faster than Leafs because of how the acceleration curve differs between the two vehicles. My Leaf has well over double the horsepower of my gas car, but my gas car could still beat it in a race to 70 mph.

If you spent 130k+ for a P85D, I don't see how 3k + installation costs is the straw that broke the camel's back, in making your P85D a non-worthwhile purchase. Especially given the fact that it brings your sports car 0-60 time into supercar territory.
 
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Tesla never lied about the 691 hp, they were however deceptive by having this "motor power" figure as the only power figure, and by not correcting the misconception that the media and general public has that the car can actually output this power at any point in time. Not cool. What they seem to have lied about was an incoming free OTA improvement of P85D *at high speed*. This fuse upgrade seems to achieve that, but it's far from free... Really not cool for people who bought a P85D at the time, taking this promise (commitment?) into account. Why does Tesla keep doing this (this being mismanaging expectations), it's so unnecessary...
 

sorka

Well-Known Member
Feb 28, 2015
9,866
8,041
Merced, CA
Tesla never lied about the 691 hp, they were however deceptive by having this "motor power" figure as the only power figure, and by not correcting the misconception that the media and general public has that the car can actually output this power at any point in time. Not cool.

Agreed. Not cool. And Tesla has never used the defense that several others have saying that since the individual motor ratings add up to 691 that they're not lying or wrong even though the motors never output that power combined at any one point. Even at 33 MPH where the peak 414KW hits, the power to the wheels is barely more than 436 with the two publicly published dynos.

I've been defending them in a different way than those who've used the "motor power" excuse. I've been saying all along that I believed they were going fix this with a software update or make it right in some way. I really hope they still do but obviously it won't be a software update alone at this point.
 
The P85D can't produce more than 414KW with the current pack so what he told you is note remotely possible. If it is, they damn well better do it for free since we're getting 150 hp less than what we paid for in the first place.

Sorka: I believe your statement above is _almost_ correct. It would be entirely correct if you swap "with the current pack" with "with the current fuse/contractor". The limiting factor for the current P85D is not Energy (ie pack size), but rather Power (how quickly the energy can be tapped). The current fuse/contactor on the current P85D can't handle anything beyond 1300 amps. They heat up and blow beyond that. The new fuse and contactor is an advanced design using better high temperature material, and can safely draw up it 1500 amps. With these new components in place the dual motors can safely draw higher power from the existing P85D pack, achieving ludicrous mode on 85kwh pack.
 

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