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That Tesla Data: What It Says and What It Doesn’t

wheels.blogs.nytimes.com

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Re: That Tesla Data: What It Says and What It Doesn’t

#271

Post by PebblesRox »

bjourne wrote: post #242
PebblesRox wrote: post #204

Earlier quoted context omitted.

Point 4 of this article suggests that accelerating in short bursts with long coasts in between works best for gas-powered cars. I can see how turning off cruise control could be more efficient in this case too, although I agree braking would be silly. http://www.mrmoneymustache.com/2011/07/26/hypermiling-expert...

No it doesn't. What the article says is to keep your velocity constant = zero acceleration by coasting and giving gas in short spurts. But it's entirely possible that journalists don't know the difference between "giving gas" and "accelerating the car."

I don't think the pulse and glide method keeps your velocity constant. The idea is that accelerating to 70mph and coasting down to 50mph repeatedly is more efficient than maintaining a constant speed of 60mph. Not always more practical, but you should try to drive that way when you get a chance. Here's another explanation: http://www.metrompg.com/posts/pulse-and-glide.htm

Re: That Tesla Data: What It Says and What It Doesn’t

#272

Post by PebblesRox »

bjourne wrote: post #242
PebblesRox wrote: post #204

Earlier quoted context omitted.

Point 4 of this article suggests that accelerating in short bursts with long coasts in between works best for gas-powered cars. I can see how turning off cruise control could be more efficient in this case too, although I agree braking would be silly. http://www.mrmoneymustache.com/2011/07/26/hypermiling-expert...

No it doesn't. What the article says is to keep your velocity constant = zero acceleration by coasting and giving gas in short spurts. But it's entirely possible that journalists don't know the difference between "giving gas" and "accelerating the car."

I don't think the pulse and glide method keeps your velocity constant. The idea is that accelerating to 70mph and coasting down to 50mph repeatedly is more efficient than maintaining a constant speed of 60mph. Not always more practical, but you should try to drive that way when you get a chance. Here's another explanation: http://www.metrompg.com/posts/pulse-and-glide.htm

Re: That Tesla Data: What It Says and What It Doesn’t

#273

Post by drbawb »

redm wrote: post #211
andrewfelix wrote: post #192

Earlier quoted context omitted.

"reads like Broder was trying to stack the deck" I disagree. I think Broder is doing what a lot of journalists do and has accentuated the overall negative experience to create a better narrative. In spite of the poor communication and slight exaggeration, I don't feel like there was malice or a great deal of intent on Broder's behalf. He generally had a poor experience. The errors in his story do not negate that, and…

> In spite of the poor communication and slight exaggeration, I don't feel like there was malice or a great deal of intent on Broder's behalf. He generally had a poor experience. I don't know much about electric cars, but I do know this: They aren't great for long distrance driving. I have no doubt that Broder had a bad experience. When it's 10 degrees outside, I don't want to turn off the climate control. When I'm d…

>when it's 10 degrees outside.

Not too long ago we had a week or so of 0-10deg [F] weather in the midwest, and my _petrol_ car didn't give me heat for most of my commutes.

What little heat I did have, I voluntarily left to the engine so it could get up to temp [knowing this is better for my car, and my emissions].

If it's going to be that cold, I bring an extra pair of socks and gloves. I don't blame my car that I _know_ is struggling to keep itself at operating temperature.

Not to mention, he had heated the cabin up to 74degF prior to that; no journalist can reasonably expect me to believe that a _brand new_ luxury electric car has worse insulation than an 01 Camry with cracked weather seals on the rear doors.

I'm sorry, but unless you didn't read the weather report and packed shorts and t-shirts, there is no way that 10degF ambient temp, in a well sealed cabin that has previously been heated to 72degF, is "white knuckle" weather.

---

I certainly agree with you, and with what I think was the larger point of Broder's review: this is not a _no compromises car_, even CNN's reviewer said that he had a bit of range anxiety on the longest leg.

Charging for an hour is a _compromise_, and criticizing it is well deserved.

A photo-op of the Model S on a flatbed truck, saying it broke down? That's no longer fairly deserved criticism: especially when you pulled out of a station with 32mi. of est. range for embarking on a 61mi. trip _knowing_ the battery was having range problems b/c of the weather.

That being said, considering this is a performance oriented car, I think the mileage was quite remarkable for an all electric vehicle. I'm honestly impressed, and I'm a petrolhead.

Once the fast-charge network is a bit more built-up? I can easily see myself planning long road-trips around it. -- On vacations we regularly spend 30-45 minutes at a filling station between tanks. Not because we _have to_, but because we need to stretch our legs, rotate seats, eat lunch, buy more snacks, maybe pick up a book, double check routes and reservations, etc. etc. I don't think an hour at a station that has plenty of amenities is unreasonable for 200+mi. legs.

Re: That Tesla Data: What It Says and What It Doesn’t

#274

Post by jellicle »

andrewfelix wrote: post #225
onemorepassword wrote: post #221

Earlier quoted context omitted.

I agree that this is what journalists do. It's also why the public stops trusting journalists, especially after they've personally experienced this. It's what the rest of us calls "lying". This may not be an example of individual malice, but it is definitely an example of why journalism that still uses practices that pre-date video, let alone the internet, no longer commands any kind of respect. Broder lied "because…

I wouldn't characterise it as lying. Broder constructed a narrative around his experience, and got a couple of the details wrong.

Actually, Broder constructed an experience around the narrative that he had wanted from the beginning.

Driving like a normal person would - letting the car charge and trying to keep it near full - wouldn't have matched the narrative he had in mind, so he didn't do it. The narrative he had in mind involved desperately limping from station to station trying to get a little juice, so that's the experience that he constructed.

How an unbiased reporter would have done it: charge to full, pay attention to mileage and time to charge, repeatedly charge to full throughout trip, discuss the time limitations (must stop for an hour+ on long trips instead of a ten minute gasoline stop...), see if mileage matches expectations, and so on.

That wasn't the story Broder had in mind.

Re: That Tesla Data: What It Says and What It Doesn’t

#275

Post by danielweber »

ChuckMcM wrote: post #266
awolf wrote: post #181

Earlier quoted context omitted.

The "fundamental attribution error" refers to our tendency to overattribute others' behaviors to their dispositions, while reversing this tendency for ourselves. From: http://lesswrong.com/lw/hz/correspondence_bias/ Also, this: We tend to see far too direct a correspondence between others' actions and personalities. When we see someone else kick a vending machine for no visible reason, we assume they are "an angry pe…

I just hate vending machines, the way they stare at you and tempt you with unhealthy treats. Kicking them reminds them they are not yet the dominant species on the planet.

http://qntm.org/vending

Re: That Tesla Data: What It Says and What It Doesn’t

#276

Post by freyr »

jychang wrote: post #258
slantyyz wrote: post #106

Earlier quoted context omitted.

This is what bugs me the most about this whole thing. If the Tesla people on the phone with the reporter had just erred on the side of caution with their advice, the whole debacle would have been avoided. Broder complaining about a couple of extra hours charging would have just come across as a nitpick.

Why should they? They were just reps on the phone talking to a guy who was reviewing superchargers, not planning for a media battle. I don't see how they would have prepared for anything other than the standard advice and it would be surprising if they did.

> I don't see how they would have prepared for anything other than the standard advice

The point is that their standard advice should err on the side of caution, not leave motorists stranded. Regardless of whether they work for the NYT.

Re: That Tesla Data: What It Says and What It Doesn’t

#277

Post by bathat »

codex wrote: post #38

The tit-for-tat details here don't matter. The story is simply, "The Tesla lost a ton of range overnight, unexpectedly. Tesla said it would come back after an hour of low-power charging." Is that true? Clearly the former statement is true but the latter is not. The only question is whether Tesla gave the reporter bad advice, or whether the reporter lied because he wanted to sabotage the test. Given Tesla's focus on t…

>The story is simply, "The Tesla lost a ton of range overnight, unexpectedly. Tesla said it would come back after an hour of low-power charging."

But why is that the story? The story could just as easily be, "The NYT reporter stopped charging when the battery was less than 3/4ths charged and subsequently couldn't finish his trip. He experienced some unanticipated range loss overnight, but it was less than what he would have needed to finish his trip."

Re: That Tesla Data: What It Says and What It Doesn’t

#278

Post by codex »

bathat wrote: post #277
codex wrote: post #38

The tit-for-tat details here don't matter. The story is simply, "The Tesla lost a ton of range overnight, unexpectedly. Tesla said it would come back after an hour of low-power charging." Is that true? Clearly the former statement is true but the latter is not. The only question is whether Tesla gave the reporter bad advice, or whether the reporter lied because he wanted to sabotage the test. Given Tesla's focus on t…

>The story is simply, "The Tesla lost a ton of range overnight, unexpectedly. Tesla said it would come back after an hour of low-power charging." But why is that the story? The story could just as easily be, "The NYT reporter stopped charging when the battery was less than 3/4ths charged and subsequently couldn't finish his trip. He experienced some unanticipated range loss overnight, but it was less than what he wou…

I think many people assume you should always charge a Tesla fully "just in case", but that takes much longer (hours longer) than filling up at a gas station. In practice people take shortcuts, especially when its freezing outside and they'd rather be arriving sooner at their hotel. Its human nature. The author's mistake is trusting the mileage reported by the car in cole weather, then trusting Tesla's PR lackey when he was told the range loss was a software glitch.

"When I parked the car, its computer said I had 90 miles of range, twice the 46 miles back to Milford. It was a different story at 8:30 the next morning. The thermometer read 10 degrees and the display showed 25 miles of remaining range"

Re: That Tesla Data: What It Says and What It Doesn’t

#279

Post by bathat »

manacit wrote: post #169
tunesmith wrote: post #162

I put a graph together showing all the points/counterpoints and here's what I'm left with. - not charging past 90% at the 1st station is defensible. Especially if Tesla warns it will shorten the battery's life. - It'd be better if Tesla's software took temperature into account when estimating mileage range. - Broder is being ridiculous about the cruise control and his speed estimates, and the temperature. He has part…

Most of this analysis is spot on in my opinion - the one area I disagree with you in is the portion where he allegedly drove in circles. The graph Tesla shows is misleading and completely blown out of proportion. 0.6 miles is not very far to travel, especially when 0.2 miles are accounted for by the offramp. A drive once around an unfamiliar parking lot in the dark, looking for a small charging station can easily acc…

Part of the problem is that in his latest rebuttal, Broder turned off the map layer of the Google image he used. If he had left it on, you would see that many of the "streets" in that rest area are one-way. The only place he could have driven is around the two rightmost rows of parked cars. You really must have a very strong suspension of disbelief if you think he passed the Superchargers five times without seeing them.

What really makes Broder's account unbelievable is that his original story was a review of the Supercharger network. His review completely omitted any mention of the difficulty of finding the charging stations. Why would he do that? As concerned as he claimed to be about not reaching the next charger, why did he never mention that he had to spend precious battery finding the damn thing until Musk accused him of driving in circles? Might it be possible that "searching for the charger" is just an excuse invented after his odious behavior was discovered?

Re: That Tesla Data: What It Says and What It Doesn’t

#280

Post by jimmyyoung »

bmj wrote: post #139
jimmyyoung wrote: post #87

Earlier quoted context omitted.

Musks blog post is meant to be technical. It's not directly towards the average Tesla customer. The average customer is probably not going to be following this. Thousands of newspaper are going to write an article everything that happens. They will make it more reader-friendly. Repeat: It is not Musks' intent for customer to read his blog.

The average customer is probably not going to be following this. I wonder about that. I mean, if you are a Tesla customer (or a would-be Tesla customer), I reckon this story has come across your radar, given the sort of online media coverage. Certainly, the average customer may not read Musk's blog, but again, given that this story has been picked up by quite a few outlets on the web, I bet customers are reading it.

Sorry let me clarify. I meant they are not going to be following the blog. They will be definitely be following the story :)
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