Hacker News Reader

> articles like this really annoy me, as they don't provide any meaningful substance

If you've thought about owning an electric vehicle, one of the first thoughts that pops into your head is "what happens if I run out of juice in the middle of nowhere?" Including questions like "How does the car behave? Does it just shut off?" to "How does AAA handle it?" to "How hard is it to get going again?" A lot of other commenters are raising points that the author was kind of a dumbass. But as it turns out, I too fuck up every so often, so I'd like to know what happens when I do.

The article goes a long way towards answering those questions. I'm probably not going to get an electric car anytime soon but I don't see anything in the article as particularly anti-Tesla or even anti-electric.

I guess being a car enthusiast, I am not surprised a tow company refused to tow an expensive car they are not familiar with. When the 350Z just came out and was relatively rare, some tow companies refused to deal with them because they required a flatbed and special care due to super low clearance.

This is relatively common, though not in issue in most large metro areas.

What I don't understand is why the car didn't use route information in range estimates (assuming they entered their destination). It would have known about elevation changes. If getting map information from Navteq then it could also know about average speeds and historical traffic patterns.

It could also have given more driving guidance. I didn't see how they came up with 63mph, but the car itself should know about energy-speed tradeoffs could have told them a more appropriate speed to go.

And if knowing they wouldn't reach a charger it could have had them stop closer to somewhere that could help, or direct the AAA equivalent to them for the moment they ran out.

People keep mentioning the mental effort of electric cars for these issues, but the car itself can address those and do so far more effectively.

Even if you did all this, you can't predict everything in advance especially on a long trip.

Trying to drive anywhere cutting it this close, in any car, is likely to leave you stranded.

They started out with a ~15% margin. How close is acceptable?

Behind the scenes the mileage estimates are really a central number with error bars. In this case the electronics could definitely have come up with better numbers based on altitude changes. And it definitely could have given guidance on speeds to maintain whatever margin is comfortable.

Had no idea a Tesla could do that! A really good question then...

I really wonder if they purposely did this to try and make it close and get a good article. Had the car not ran out of juice they would have a very boring article.

Like most Top Gear episodes, it's the story not the car that makes viewers tune in. Everyone knows that the races are scripted.

I don't understand. The fully-charged range is 265. They're mostly-charged and have an estimate of 247 miles. The actual path they want to take is 209 miles. Having a range only 80% of estimated is newsworthy, in a car which doesn't have a lot of infrastructure around to give it juice.

The article also wasn't just about the range; it covered several other topics as well. One of those topics is the difficulty of getting towed. It doesn't matter how many times you say "well, duh, use it according to spec", humans are humans, and they will run out of juice in their vehicles, particularly in limited-range vehicles with little refueling infrastructure. They couldn't even get the car onto the truck without a Tesla guy to power it enough to shift it into neutral, so even if they had found an earlier towing service that didn't fob them off, not being able to be put in neutral is still a problem in regards to towing.

There's plenty of newsworthy stuff in this article, it talks about one experience of when things go wrong. There's also plenty of articles talking about how great the car is - should we say that they're also not newsworthy, because there have already been glowing reviews?

So they left on a long trip with a 93% charge knowing that it was going to be close and fell short by 3 miles... why is this news or article worthy?

The next time the writers need to make a story I can loan them my Transit Connect. It never gets within 10% of its "distance to empty" for a full tank, even in optimum conditions.

Boom! Byline.

I don't think it's safe to assume the car was at 93% charge based on the reported 247 mile estimated range. It's not clear to me that the car will always show estimated range to be 265 when charge is 100%.

Range estimation is a lot more complicated than 'percent of max power stored' * 265. Obviously Tesla's algorithm was too optimistic in this case, even though there seemed to be some 'safety margin' at the start.

I'm sure Tesla has a great deal of data on the variance of miles covered on a full charge over all sorts of terrain, climate, traffic, driving patterns, etc. and I would assume they use that data to build a decent range predictor. Probably the hardest part is not so much getting a good prediction from given set of inputs, but actually getting decent inputs to feed into the predictor. Driver enters the destination address, but after that... is the car pulling temperature, wind speed/direction, elevation delta, statistical traffic patterns, live traffic, etc...

OK... After considering all that, maybe we just implement 'percent of max power stored' * 265 and call it a day. (It's like the 80/20 rule has become the 80/1 rule -- so often now I feel like you can make something 80% as good, for 1% the effort.)

724 PM PDT TUE APR 29 2014
...WIND ADVISORY REMAINS IN EFFECT UNTIL 3 PM PDT THURSDAY...

WINDS...NORTHEAST WINDS 15 TO 25 MPH WITH GUSTS TO 40 MPH WILL INCREASE TO 20 TO 30 MPH WITH GUSTS TO 50 MPH LATE TONIGHT THROUGH WEDNESDAY. ISOLATED DAMAGING GUSTS NEAR 60 MPH WILL BE POSSIBLE IN THE FOOTHILLS. WINDS ARE EXPECTED TO BE SLIGHTLY WEAKER WEDNESDAY NIGHT INTO THURSDAY.* ==============

Accurate range prediction in this neck of the woods also needs to account for the weather.

Sustained 30-40mph gust 60 is not uncommon in so-cal/desert.

Point your EV into that for an hour on i-5 and ...

You will lose some range for sure.

Yeah, its like going uphill constantly and maintaining some good speed is not going to decrease the range. ANY petrol or diesel car will get decreased range. Usually range is estimated based on previous rides - what they should do is - just reset the range estimate. They would get up to date data within 15 minutes of drive.

Estimated range is not fool-proof. Common sense should be applied to everything - even technology packed car.

many electrics and hybrids systems don't seem to encourage hypermiling, like very aggressive off throttle regeneration and such. Not owning a Tesla, nor interested in one, I would like to know just how possible hypermileing is?

Can you toggle the regenerative effect when you lift off the pedal? Like just when your about to crest a hill, they quickly toggle it on once you get + over the speed limit on the downhill side?

I can hit some pretty astounding numbers in my TDI Beetle vert with really simple tricks but that does rely on the fact that I can pretty much stay in high gear so engine braking isn't a factor, only danger being stalling. Engine uses no fuel without throttle input unless you put the clutch in.

>Can you toggle the regenerative effect when you lift off the pedal?

You can, but this would slow you down more than gravity, the transmission, and the friction of the road alone would.

The only thing you can really do is change to neutral. Dual-clutch transmissions in high-end sports cars have already been doing this for years, though they don't do it based on the angle of the road surface, since if you're going fast enough, it's beneficial to do it as often as possible.

My understanding (not a Tesla vehicle owner) is that you may pick the regenerative mode of the car: low or standard. Low allows for the coasting experience of driving a car with an Internal Combustion Engine. Standard allows the electric motor(s) to slow down the vehicle when the pedal is let up for regenerative effect.

In either scenario, I believe both the motor and disc brakes are utilized when the brake pedal is depressed; however, the general theme is that more kinetic energy is lost to thermal from disc brake friction in the Low scenario.

My thoughts are that regeneration of the battery is encouraged, but the marketing of the Model S appears such that Tesla Motors wants to deliver EV luxury & performance first, and foremost and then cleverly extend it behind the scenes in such a way that the user need not think about it. To me, it's not all that different from flagship smartphones. Actively 'hypermiling' a flagship smartphone for battery life would compromise many of the flagship features... which aren't suprisingly luxury and performance.

So they left on a long trip with a 93% charge knowing that it was going to be close and fell short by 3 miles... why is this news or article worthy?

Exactly. And this is through the desert. This approaches the darwin award threshold.

Also, the article neglects to mention the number of chevrolet cars that caught fire during his trip.