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Comment Re: We'll be fine. (Score 2) 201

For some more figures....

Porsche Cayenne: Baseline (2012 and earlier) 7,3sec; Diesel V6 (2013) 6,8 sec; Diesel V8 (2013) 5,3 sec; S (2011) 5,6 sec; S (2015) 5.1 sec; S hybrid (2011) 6,2 sec; S E-hybrid (2016) 5,2 sec; Turbo (2015 and earlier) 4,2-4,3 sec; Turbo S (2016) 3,8 sec.

Ford Mustang: Ecoboost (2015, various): 5,3-6,0 sec; V6 (2016): 5,3 sec; GT (2015, various) 4,3-4,7 sec

It's funny how much we've gotten used to these sort of performance figures being affordable (mid-5 figures). 5 seconds was supercar speeds back in the 1980s (e.g. 1985 Ferrari Testarossa). Nowadays, for an econobox you get figures like 8,3 sec (2016 Civic EX sedan); 8,0 sec (2017 Camry XSE); etc. And even the econoboxes have options to improve performance - for example for $35k you can get a Camry getting closer to a baseline Model 3's performance (XSE V6, 6,1 sec), and Honda has the sporty Civic Type R beating a baseline Model 3 (4,9 sec) for around the same price (although with less impressive standard features and much higher operating costs). By comparison, the 1973 Honda Civic had a 0-60 of 19,1 sec ;)

Comment Re: We'll be fine. (Score 3, Informative) 201

I don't understand either of the above posts.

5.6 seconds is the acceleration of a low-end Mustang (which also costs about the same as a baseline Model S). A typical econobox sedan these days does it in about 8 seconds, more like 9 for a typical crossover. On the opposite side of the spectrum, the fastest Veyron is 2.4, and the fastest Model S 2.34. The performance option for the Model 3 hasn't been announced (although it's been announced that there will be one); I'd expect it to be in the 3.5-5 second range, depending on a lot of factors. It won't be able to hit the top S speeds because it can't support as big of a pack; nor would Tesla want to make it be able to, as they want to have a reason for higher-end buyers to choose the higher-end vehicle class (Model S).

As for driving range: the more powerful you make an EV, the further it's range. It's the opposite of gasoline vehicles. In addition to needing a larger pack for more power, more power also means lower resistance conductors; this means lower energy loss at cruising speeds.

Now, if the GP meant "if you're constantly pushing a vehicle to its limits, you go a shorter distance with a more powerful vehicle", that's obviously true for both EV and gasoline. But range figures (for both EV and gasoline) are not for track duty, they're for normal road duty.

Comment Re:Why am I not surprised? (Score 1) 304

I understand how this might confuse people as I had the same misunderstanding of heat pumps myself.

I have no confusion about heat pumps. The standard for cold weather with a reversible heat pump is to combine it with resistive heating. Preferably high voltage resistive heating with PTC heating elements. Heat scavenging from the drivetrain further improves performance.

No, you don't. The batteries need to be protected from being frozen.

A cruising li-ion EV on the highway is putting 300-400W into its battery pack, a couple hundred into wiring, and perhaps 800W into each of the motor and inverter. You can take power from the latter three at will. The former you can take at a rate slower than it enters, assuming that it's preheated and that said rate is positive; if it's cold enough and poorly insulated enough, then heat loss is greater than incoming heat and you have to use resistive heating and/or scavenged heat from the drivetrain.

Not all EVs make good use of heat scavenging, but at least the Model S does a good job scavenging it. Which is why heating doesn't cut as much of the range as you'd expect. For example, at 120kph / -20C the 75's range drops from 328km to 293km by using the heater - 11% for nearly three hours of heating at a quite cold external temperature.

Comment Re: Why am I not surprised? (Score 1) 304

You realize that a commercial driver that stopped for only 15 minutes every several hours in the EU would be fined and potentially stripped of their license, don't you? Law requires 45 minutes per 4 1/2 of driving. Why? Because long stretches without having a legitimate break are not safe. The longer you drive for, the more likely you are to get into an accident.

Also, for that matter, do you not eat? Or do you eat behind the wheel also, further increasing your risk of an accident?

Comment Re:We'll be fine. (Score 4, Insightful) 201

Apparently where you live a $16k car does 0-60 in 5.6 seconds (base model, not performance model), has front and side collision avoidance (standard), drives for 2-3 cents per mile and has 1/10th the moving parts of a normal car.

Hey, while you're at it, why not compare it to a Tata Nano? Or a used Yugo held together by duct tape?

Is it the bottom of the market? No, of course not. In fact, there's nothing about it that could be described as bottom of the market. But $35k is neither out of the ordinary for a car of its featureset / performance, nor some sort of unaffordable luxury cruiser or supercar. And they did this in half a decade from a small two-seat six-figure car. I mean, for crying out loud, how fast of a price reduction would make you happy? They've furthermore laid out clear plans to continue the price reduction trend, with Gigafactory and its successors. Even at the current price, their current preorders amount to over a year's wait at full production.

That some people find this to be some sort of slow pace of advancement and scaleup boggles the mind. It's like having to wait 8 seconds to heat up some food and complaining, "Come on!!! Isn't there anything faster than a microwave?" And at the same time you see the same people complaining that Tesla has to keep doing financing rounds rather than paying dividends. So they're apparently supposed to take their current supermassive production scaleup / price scaledown curve, increase it severalfold, and do that without investor money.

Comment Re:No unicode on Slashdot. (Score 3, Interesting) 482

Exactly what I've been asking for for ages!

Slashdot doesn't need to allow all of unicode (feel free to leave out emoji, for example), but at least allow common letters and symbols. Slashdot's current behavior - silently stripping them - is terrible. It can distort the meaning of text - when talking about foreign matters, when using math / science symbols, etc. It's made me look like an idiot several times - e.g. there's a world of difference between "My morning coffee is fine, but 10(DEGREE MARK) more would be perfect" and "My morning coffee is fine, but 10 more would be perfect". And thorn is a common letter where I live, so whenever I mention people or place names from where I am they get mangled. I've also had problems copy-pasting text from other sites that happened to have unicode symbols in them. On occasion, rather than silently stripping them, Slashdot has instead transformed them into gibberish.

Comment Re:Heating and charging - both solved issues. (Score 1) 304

And my reaction to the guy going the aforementioned 1836 miles in 24 hours on public roads: it's a shame he wasn't arrested for endangering the public. Sleep deprivation combined with high speeds is nothing to boast about.

Today's crop of electric vehicles lets you do cross country trips as fast as is safe to do. The charging "downtime" is roughly the same people are supposed to take (and commercial drivers are required to take in many countries). For example, in the EU it's "a break or breaks totalling at least 45 minutes after no more than 4 hours 30 minutes driving". A commercial driver doing more than that is breaking the law.

Comment Re:Why am I not surprised? (Score 1) 304

Air conditioners are not reversible heat pumps, which is what you need to be able to use it for heating.

Honestly, it surprises me that a reversible heat pump would be that much more expensive or massive than a standard AC unit, but so far very few EVs have used them, so I have to assume that they are (probably due to the small market at present).

Back to the GGP, it's also worth noting that while EVs only give off around a quarter as much heat as an ICE, they still do give off heat - in the battery pack, wiring, inverter, and motor, and all of them are typically fan- and/or ram air cooled. If you're cruising at 10+kW power, you still have the potential to draw the equivalent heat of a small portable space heater off of your powertrain. Whether it's worth the cost/mass/complexity to do so, that's another story...

Comment Re:Why am I not surprised? (Score 1) 304

You know, I've long been dismissive of solar power on EVs, but actually, those numbers aren't that bad.

20% isn't "impressive" any more, you can get 20% efficient cells quite affordably - some brands of common rooftop panels are over 22%. Even if you limit yourself to cheap thin film solar, there's several selling in the 17% range. On the other hand, if you have a large budget, you could cover the vehicle in Spectrolab/Soitec/Fraunhofer multijunction cells with microconcentrators and get 30-40% efficiency.

On the road on a sunny day you have full "exposure" unless you're driving through the woods or an urban canyon. You can certainly cut the power down by solar angles (aka, not "peak sun"), but then you can't separately cut it down with your "5 hour" limitation.

17 miles is longer than the average American's commute. And commutes often involve city driving; the 215-mile Model 3 range is for highway driving, not city. EVs get much better range in city driving than highway. And the depth of discharge isn't 100%, a (small) portion of that 60kWh is reserve at the bottom and unused at the top. On the other hand, you didn't factor in charging losses, and light that hits the windows has only partial charging potential (if that) - but these losses are smaller than the range gain for mixed driving vs. highway-only and accounting for DoD.

And lastly, "not really enough to be useful if you run out of charge on the side of the highway." - really? How far did you miss the charging station by? Are you picturing that if you're going to miss a charging station it's going to be dozens of miles? How the hell did you do that? And if you're that bad at trip planning, how did you ever manage to drive a gasoline car?

Modern EVs know where all nearby charging stations are, and there's fast charging stations regularly spaced on almost all US interstates. If you're missing charging stations by dozens of miles, there's something seriously wrong with you.

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