P85D motor hp controversy starts also to show in U.S. media

[Luclyluciano]

If a manufacturer ships a car that claims 1000hp, and there is no legal speed at which it has the traction on any road to output that 1000hp, can they still claim 1000hp? *cough* hellcat *cough*. Should return it back to Dodge "I press the pedal but I don't accelerate like I have 707hp, I just see smoke"

Sure, the hellcat is not AWD, but it still produces 700 HP and is very fast. So yes they can claim their 700 HP output because it is real.

My P85D is quick off the line because of high low end torque and immediate responsiveness but it does not produce 691 HP .

 

[sorka]

You are changing the argument. Your argument is that it is common sense for a manufacturer to never be allowed to advertise a number it can't produce in any part of the car (or alternatively for them to advertise a number at a component level rather than a system level). I am saying it is not and have given an example in the car world. There is no common sense reason why it is always unacceptable to advertise at a component level.
/

It is always unacceptable advertise horsepower that a car can never achieve under any circumstances......as it was sold(I have to add that little disclaimer because then you'll go on again about future battery upgrades allowing the P85D to make more power).

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And in the ICE world, I should point out the convention has switched to SAE J1349 (aka net power) and SAE J2723 (aka certified power). There are no such conventions yet in the EV world and obviously those standards don't apply to EVs (as they assume the existence of an ICE). /

And as such, Tesla could get away with advertising GROSS power at the battery (we're just going in circles over and over) and most of us would have been fine with it. Advertising 555 at >= 90% SOC would have been fine with me until a standard is agreed upon. Any standard of which would not allow them to declare the full 555 hp because any reasonable standard for EVs will require declaring maximum power at an average daily driving SOC and not not maximum SOC since we don't get to drive at maximum SOC for most of the time. In this case, that wouldn't effect an 85D, P85, or S85, but it would effect a P85D. It will of course require measuring power at the motor shaft which would of course be lower than 555 because of inverter conversion and electricity to kinetic energy conversion.

Tesla can sort of get a pass right now to use GROSS power at the battery since there isn't a defined NET standard that takes into account the entire vehicle as delivered (if you're going to believe Vlad's interpretation of ECE R85 not using the drivetrain battery).

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Sure, the hellcat is not AWD, but it still produces 700 HP and is very fast. So yes they can claim their 700 HP output because it is real.

My P85D is quick off the line because of high low end torque and immediate responsiveness but it does not produce 691 HP .

The Hellcat is way under rated and makes more like 750 hp at the flywheel. It's likely underrated for insurance purposes. This is typical of high power cars these days to claim less than actual.

635 rear wheel hp (stock)
Dodge Challenger SRT Hellcat Dyno Tested, May Be More Powerful Than Claimed: Video

642 rear wheel hp (stock red key)
More Hellcat Power? - Dyno Comparison | SRT Hellcat Forum

A 15% drivetrain loss (rear wheel drive) puts these around or over 750 hp at the flywheel.

 

[brianman]

Porsche 918 comes to mind:
Gas engine rear = 608 hp @ 8700 rpm
Rear electric motor = 156 hp
front electric motor = 129 hp
Max system hp = 887 hp
0-60mph = 2.5 seconds
1/4 mile = 10 seconds @ 145 mph
top track speed = 214 mph

608+156+129=893hp vs.
Max system hp=887hp

So they can align the stars fully except for 6hp? Impressive.

 

[dsm363]

608+156+129=893hp vs.
Max system hp=887hp

So they can align the stars fully except for 6hp? Impressive.

Impressive but if I paid $1,000,000 for 893 hp I would feel cheated. That's what I gather is the main complaint on this thread. They are much closer than Tesla but still apparently not advertising correctly.

 

[darthy001]

Impressive but if I paid $1,000,000 for 893 hp I would feel cheated. That's what I gather is the main complaint on this thread. They are much closer than Tesla but still apparently not advertising correctly.

Well... Porsche actually lists battery power just as Mercedes. But I assume the right crowd here will dismiss those numbers just as they did with Mercedes since it doesnt fit the rest of their world view...

http://press.porsche.com/vehicles/2015/Tech-Specs-2015-Porsche-918-Spyder.pdf

Liquid-cooled, high performance lithium-ion hybrid battery; 6.8 kWh with max power output of 230 kW; Liquid-cooled, high performance lithium-ion hybrid battery; 6.8 kWh with max power output of 230 kW;charged via Porsche Universal Charger (AC) charged via Porsche Universal Charger (AC)

Edit: seems like the battery experts Tesla are the only ones not showing these numbers. Strange indeed.....

 

[Laserbrain]

WTH did my post go...? Let's see if it disappears again...

So it appears that the way Tesla listed motor horsepower is not only consistent with ECE R85, but is also consistent with the way other manufacturers (Porsche, Mercedes) list motor hp for EV multi-motor drivetrains.

So you say everybody is allowed to adopt Volkswagen's creative Diesel exhaust measuring techniques? Because you are saying wrong isn't wrong as long as others do it, right? Hey I could go and rob a bank because somebody else did it and got away with it - so robbing a bank cannot be wrong, right?

Wrong. A scam is a scam. And no amount of spinning will change this.

Or explain to me why even today the hp of the 70D/90D are given as combined hp while the P85D hp are not. There is only one explanation. One! A single word describes it. It starts with a "s".

 

[dsm363]

WTH did my post go...? Let's see if it disappears again...



So you say everybody is allowed to adopt Volkswagen's creative Diesel exhaust measuring techniques? Because you are saying wrong isn't wrong as long as others do it, right? Hey I could go and rob a bank because somebody else did it and got away with it - so robbing a bank cannot be wrong, right?

Wrong. A scam is a scam. And no amount of spinning will change this.

Or explain to me why even today the hp of the 70D/90D are given as combined hp while the P85D hp are not. There is only one explanation. One! A single word describes it. It starts with a "s".

Mod note: It's in moderation while being reviewed. Personal attacks are not called for.

 

[X-Wing]

Can someone please fill in the blanks for me?

Model	Combined Output (hp)	Front Motor Output (hp)	Front Motor Rev (rpm)	Rear Motor Output (hp)	Rear Motor Output (rpm)	Vehicle Speed (km/h)
P85D	691

If someone can fill in the blanks above, it will be greatly appreciated. I tried, but the best I have got is this so far.

Model	Combined Output (hp)	Front Motor Output (hp)	Front Motor Rev (rpm)	Rear Motor Output (hp)	Rear Motor Output (rpm)	Vehicle Speed (km/h)
P85D	691	Not	At	Any	Speed	Ever

 

[Soolim]

Impressive but if I paid $1,000,000 for 893 hp I would feel cheated. That's what I gather is the main complaint on this thread. They are much closer than Tesla but still apparently not advertising correctly.

Not cheated if those numbers were published to the public, and the buyer can make an informed decision if the 6 hp is material or not prior to the purchase. Did Tesla provided the same level of detail to the public prior to the complain?

 

[brianman]

Impressive but if I paid $1,000,000 for 893 hp I would feel cheated. That's what I gather is the main complaint on this thread.

We interpret things incredibly differently then. Either that or you're intentionally trying to upset people.

 

[stopcrazypp]

It is always unacceptable advertise horsepower that a car can never achieve under any circumstances......as it was sold(I have to add that little disclaimer because then you'll go on again about future battery upgrades allowing the P85D to make more power).

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And as such, Tesla could get away with advertising GROSS power at the battery (we're just going in circles over and over) and most of us would have been fine with it. Advertising 555 at >= 90% SOC would have been fine with me until a standard is agreed upon. Any standard of which would not allow them to declare the full 555 hp because any reasonable standard for EVs will require declaring maximum power at an average daily driving SOC and not not maximum SOC since we don't get to drive at maximum SOC for most of the time. In this case, that wouldn't effect an 85D, P85, or S85, but it would effect a P85D. It will of course require measuring power at the motor shaft which would of course be lower than 555 because of inverter conversion and electricity to kinetic energy conversion.

Tesla can sort of get a pass right now to use GROSS power at the battery since there isn't a defined NET standard that takes into account the entire vehicle as delivered (if you're going to believe Vlad's interpretation of ECE R85 not using the drivetrain battery).

My point was that GROSS power as used by automakers before the 1970s is a "horsepower that a car can never achieve under any circumstances......as it was sold". GROSS power allowed automakers to use different intake, exhaust headers (with no cat), ignition timing, carburetor/fuel injection settings, not present in the car as it was sold, as well as ignoring parasitic loads (including those required to run the ICE itself like oil and water pumps). It did not represent what the car can achieve as sold, but rather what a component (the engine) could achieve, yet that was found acceptable to people.
http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/

So there is no common sense reason for that to not be acceptable. All it depends is on how the industry convention goes and right now we don't have an agreed upon convention for EVs in regards to advertising at component or system levels (there is typically no difference between the two however for most standard power EVs though, only for high performance ones).

 

[Andyw2100]

My point was that GROSS power as used by automakers before the 1970s is a "horsepower that a car can never achieve under any circumstances......as it was sold". GROSS power allowed automakers to use different intake, exhaust headers (with no cat), ignition timing, carburetor/fuel injection settings, not present in the car as it was sold, as well as ignoring parasitic loads (including those required to run the ICE itself like oil and water pumps). It did not represent what the car can achieve as sold, but rather what a component (the engine) could achieve, yet that was found acceptable to people.
http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/

So there is no common sense reason for that to not be acceptable. All it depends is on how the industry convention goes and right now we don't have an agreed upon convention for EVs in regards to advertising at component or system levels (there is typically no difference between the two however for most standard power EVs though, only for high performance ones).

The main difference, though, is that at that time all the car companies were doing the same thing. So the comparisons were still, essentially, apples to apples.

Now you have all the car companies using a different standard. A standard that is achievable in the cars. But since there is no EV standard yet, Tesla decides it's an OK idea to display the maximum power in a way that isn't actually achievable in the car, knowing that it will make the car look better by comparison than it really is.

That just wasn't right, any way you look at it.

 

[cynix]

My point was that GROSS power as used by automakers before the 1970s is a "horsepower that a car can never achieve under any circumstances......as it was sold". GROSS power allowed automakers to use different intake, exhaust headers (with no cat), ignition timing, carburetor/fuel injection settings, not present in the car as it was sold, as well as ignoring parasitic loads (including those required to run the ICE itself like oil and water pumps). It did not represent what the car can achieve as sold, but rather what a component (the engine) could achieve, yet that was found acceptable to people.
http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/

So there is no common sense reason for that to not be acceptable. All it depends is on how the industry convention goes and right now we don't have an agreed upon convention for EVs in regards to advertising at component or system levels (there is typically no difference between the two however for most standard power EVs though, only for high performance ones).

You keep using the gross hp standard to back up your claim that people found it acceptable to publish a number that can never be achieved. Do you not realise that we stopped accepting it 40 years ago precisely because we found it unacceptable?

 

[vgrinshpun]

Well... Porsche actually lists battery power just as Mercedes. But I assume the right crowd here will dismiss those numbers just as they did with Mercedes since it doesnt fit the rest of their world view...

http://press.porsche.com/vehicles/2015/Tech-Specs-2015-Porsche-918-Spyder.pdf

What you are apparently missing is that Porsche quotes battery power that requires a discharge of 33.82 times capacity (33.82C=230/6.8). The discharge rate is way too high to be sustained by this battery for any duration of the time which will


Edit: seems like the battery experts Tesla are the only ones not showing these numbers. Strange indeed.....

What you are apparently missing is that Porsche quotes battery power that requires a discharge of 33.82 times capacity (33.82C=230/6.8). The discharge rate is way too high to be sustained by this battery for any duration of the time which will allow notors to use this power. For comparison, assuming total throughput of the propulsion system in P85D to be 550hp (just grabbing the number used by Sorka) yields discharge rate of less than 5C. So Porsche lists peak power out of the battery, sustainable perhaps for a fraction of the second. The Porsche tiny (6.8kWh) battery can't deliver this power at the time when motors can use it. So Prosche electric motors can never deliver 286hp, because they are limited by the battery. In one sense this is exactly the same situation as with P85D, but if one wants to talk about misleading information, it is much more misleading with Porsche because they are listing max battery output which can't be achieved at the same point in time when motors reach their (max) rated power.

All of this becomes quite clear if, as I posted before, one notes that maximum electric speed of the 918 is only 93mph. Don't you think that a car that weights only 3692 lbs and has claimed 286 (electric) hp should have maximum speed much higher than 93mph?

And here is the irony this example demonstrates yet again that not only Tesla followed ECE R85 with the way they listed motor hp, they also followed the same practice as at least two other manufacturers of high power plug-in cars: Mercedes SLS Electric and Porsche 918.

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The main difference, though, is that at that time all the car companies were doing the same thing. So the comparisons were still, essentially, apples to apples.

Now you have all the car companies using a different standard. A standard that is achievable in the cars. But since there is no EV standard yet, Tesla decides it's an OK idea to display the maximum power in a way that isn't actually achievable in the car, knowing that it will make the car look better by comparison than it really is.

That just wasn't right, any way you look at it.

There is quite clear that there is no difference at all. The two other examples of high powered plug-in cars, Mercedes SLS Electric and Porsche 918, rate their drivetrains the same way as Tesla, just summing maximum output of the motors, without taking into account limitations of the battery, seemingly following ECE R85.

 

[aus]

Ford and Mazda have been forced to offer to offer compensation or buy back cars that didn't produce as much power as advertised many years ago.
As for the P85D, most people are going to expect a car that will go as fast as an ICE rated at the similar power to weight ratio.
They would also expect the car to dyno around 15-17% (20% for AWD) less than the advertised power (crank power).
The problem seems to be, there's no standard, such as SAE or DIN for rating power on electric vehicles.

This guys is hilarious. NWS language

 

[vgrinshpun]

Ford and Mazda have been forced to offer to offer compensation or buy back cars that didn't produce as much power as advertised many years ago.
As for the P85D, most people are going to expect a car that will go as fast as an ICE rated at the similar power to weight ratio.
They would also expect the car to dyno around 15-17% (20% for AWD) less than the advertised power (crank power).
The problem seems to be, there's no standard, such as SAE or DIN for rating power on electric vehicles.

This guys is hilarious. NWS language

There *is* standard for rating EV drive trains, and Tesla follows it - ECE R85. Section 5.3, Annex 2 and Annex 6 cover ratings of EV drivetrains

 

[stopcrazypp]

The main difference, though, is that at that time all the car companies were doing the same thing. So the comparisons were still, essentially, apples to apples.

Now you have all the car companies using a different standard. A standard that is achievable in the cars. But since there is no EV standard yet, Tesla decides it's an OK idea to display the maximum power in a way that isn't actually achievable in the car, knowing that it will make the car look better by comparison than it really is.

That just wasn't right, any way you look at it.

Actually we don't know what other car companies are using, because none of those numbers have been verified with the vigor we have done with the P85D. As I point out, for lower power cars (which describe a large majority of non-Tesla EVs) battery limitations are not going to show up. So even if they used the same motor power rating standard as Tesla, there is no difference between the two numbers.

The unique part of the P85D is that Tesla puts such powerful electric motors into it, that it exceeds what the battery is capable of. The closest example I have seen so far is the SLS E-cell, but there is a lack of performance information on that car. There are some hybrids posted, but the hybrids use low capacity power optimized batteries and don't have combined electric motor power approaching 700hp.

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You keep using the gross hp standard to back up your claim that people found it acceptable to publish a number that can never be achieved. Do you not realise that we stopped accepting it 40 years ago precisely because we found it unacceptable?

I'm using that example because it relates to the power issue directly and as a counter example to the notion that it is "common sense" for a component level specification to never be acceptable.

And as for the reasons why we moved away from gross power for the ICE, it was not because people found it unacceptable, but rather a whole lot of reasons in the 1970s (known as the "malaise era" in the automotive world) that made it advantageous for auto manufacturers to advertise a lower number. You can read the article I linked, but reasons cited include more stringent fuel economy, emissions, and safety standards (corresponding to the fuel crisis) and rising insurance costs. Someone brought up why they didn't switch back to gross afterwards, but I think automakers' reluctance to move from the status quo would easily explain that (and peer pressure would play a part too, there has to be a trigger point for an industry-wide move).
http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/

As it relates to EVs however, the automakers have not established a convention yet for how they are going to advertise horsepower. Tesla chose to use numbers using the same test standard as ECE R85 (used in all their conformance certificates) when they released their dual motor vehicles. As I put elsewhere, when SAE finishes drafting their standard, the industry will likely use that.

 

[darthy001]

And the answer is no. Both MB SLS Electric and Porsche 918 list combined maximum power of the motors without considering limitation of the battery, exactly the same way as motor hp is listed by Tesla.

I've posted about the SLS here.

Regarding the Porsche, it lists combined motor horsepower as 286 (129+156+rounding error). It has 6.8kW battery, which will not be able to provide output of 286hp or 213kW, as it will require discharge at the rate of 213/6.8=31.3(C), which is way too high for the automotive application. For comparison Tesla maximum discharge rate is under 5C. Additionally, it is clear that two electric motors in Posche 918 can't deliver the combined output of 286hp because they are limited by the tiny 6.8kWh battery - the car electric only speed is limited to 93mph (car weights 3692lbs).

So it appears that the way Tesla listed motor horsepower is not only consistent with ECE R85, but is also consistent with the way other manufacturers (Porsche, Mercedes) list motor hp for EV multi-motor drivetrains.

This reponse is exactly what I was expecting here. Once more other manufacturer’s claims as simply dismissed without any proof what so ever. You and others simply apply Teslas 5C-rating as the universal law here without any references and in this case it is so obviously wrong.

Your cherry-picking of the top speed is perfect in this case. As you conveniently ignore the stated all electric 0-62mph times for the 918 Spyder which come in at 6.1seconds. Not far off from the Model S 70D which is listed as 328HP... Of course the 70D weighs more, but not that much more.

So how can a 918 Spyder perform that task with a 5C-rating? Wouldn't that imply battery power of a miniscule 34KW/45hp? Porsche is without any doubt applying a completely different C-rating than Tesla. Otherwise those 0-62mph figures are not even close to being possible....

Another relevant example, to prove this point, is the BMW i3 which is a lot lighter than the 918Spyder, has 125 kW (168 bhp) and does the 0-62mph in 7.2seconds. Of course not AWD, but much lighter than the Porsche.

For fun let’s say the 918 Spyder only had 125kw just as the BMW.. That would be a theoretical C-rating of 18C for the Spyder 918 according to your own math. That’s a whole lot more than the claimed 10C of Mercedes and the 5C measured for Tesla. And I strongly doubt 125KW would be anywhere close enough to propel the 918 Spyder 0-62mph in 6.1seconds. So most likely the C-rating used by Porsche is higher than 18 as well.

But I assume you and other here will just say "the Porsche can’t possibly do the 0-62mph times they list".. Otherwise your entire argument falls to pieces here.

 

[sorka]

My point was that GROSS power as used by automakers before the 1970s is a "horsepower that a car can never achieve under any circumstances......as it was sold". GROSS power allowed automakers to use different intake, exhaust headers (with no cat), ignition timing, carburetor/fuel injection settings, not present in the car as it was sold, as well as ignoring parasitic loads (including those required to run the ICE itself like oil and water pumps). It did not represent what the car can achieve as sold, but rather what a component (the engine) could achieve, yet that was found acceptable to people.
http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/

So there is no common sense reason for that to not be acceptable. All it depends is on how the industry convention goes and right now we don't have an agreed upon convention for EVs in regards to advertising at component or system levels (there is typically no difference between the two however for most standard power EVs though, only for high performance ones).

You keep missing my point. Would it be proper to list the total horsepower the car can make by listing the maximum battery output actually achieved? No. Of course not. This would result in 555 hp >= 90% SOC. The actual power at the motor shafts will be less due to conversion losses. My point is that if the P85D actually put out 525KW and Tesla claimed 691 hp, this would STILL be cheating, but it would at least have been a real horsepower figure achieved somewhere even if before accounting for inverter and electric to kinetic energy conversion.

Every time I say GROSS, you try to derail my point by saying GROSS means different intakes and exhausts and no accessories so they can measure the maximum GROSS ICE power. When I say gross, I mean power measured before subtracting for things that could reduce power. In the case of an ICE, it's what they're attaching or not attaching to the engine. In the case of the Tesla, it's power as far upstream as you can get before conversion losses or electric accessories reduce power.

There is no NET standard for EVs right now that includes measuring horsepower at the motor shafts after accounting for the things that reduce power after the battery. My point is if they just want to bypass that and declare power upstream before any of that I'm fine with that. It would have at least been a real number. I'd still prefer actual horsepower quoted as measured from the motor shafts.

A NET power standard that takes into account these things plus the average daily driving SOC of the battery would be ideal and would provide the best apples to apples comparison to ICE vehicles.

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There *is* standard for rating EV drive trains, and Tesla follows it - ECE R85. Section 5.3, Annex 2 and Annex 6 cover ratings of EV drivetrains

No there isn't.

If we believe your interpretation of R85, then there is no standard for rating vehicle horsepower for EVs.

If we believe your interpretation, that standard specifies motor capacity which is not achievable in the shipping vehicle and is not a substitute for declaring vehicle horsepower.

Don't make me copy and paste my bullet list again

 

[JonG]

I still don't get why a 70D is rated way less than the sum of its motors but a P85D isn't.

but nobody wants to answer that and the only person I've seen acknowledge the question suggested we shouldn't confuse matters. There's no confusion in my mind, it's exactly the same logic, or should be.