The WindowLicker:  However, if the efficiency of the motor and the regenerative braking system are high enough, a consumer auto can get better energy efficiency at low speeds.  While no energy system is 100% efficient (thermo kills that) if your regenerative braking system captures a significant amount of your acceleration energy, then it is possible that your combined power losses to rolling/mechanical friction, and power transmission and regeneration, are going to be lower than the aerodynamic drag at high speeds.   Remember friction is proportional to velocity, while drag is the square of velocity.

Except for a little bit of a problem at the end there (friction, at least in the technical sense, does not depend on velocity -- this is Coulomb's law) everyone who posts in this thread now having not read your post should be hit.

MrSteve007: "I always arrive with quite a bit more energy (at least 10% more) when driving on the high traffic days."

CSB?  I'm not sure I see the point.  But since you mention it: how much energy do you think you'd have left if you tacked on 'only' 2 miles of Manhattan detour?

inner ted: ukexpat: ChuckNorrisSays: Jeremy Clarkson is an assbag.umad

Possibly, but he did punch Piers Morgan in the face, so he does have that going for him.
is this true?

he's even more awesome than i previously thought

even robert smith of the cure agrees
[www.ridelust.com image 300x200]

Yup it's true alright: http://en.wikipedia.org/wiki/Jeremy_clarkson#Piers_Morgan_feud

syberpud: Journalists are not renowned for their knowledge of fields other than journalism.

Period.

And that's not even including the silicone-injected bobblehead shills that Fox employees.

evaned: "... I wonder if you lose energy going faster too. Like, perhaps air drag increases. "

Who are you people?  Are you farking serious?
Of course you're less efficient at high speeds than at optimal speeds.
But the author of the 'review' claimed he had the cruise control set at 45mph.
So we're not talking about stop-and-go vs 95mph.

Do you really think Manhattan stop-and-go is more efficient than 45mph on the highway, because of drag?

evaned: Except for a little bit of a problem at the end there (friction, at least in the technical sense, does not depend on velocity -- this is Coulomb's law) everyone who posts in this thread now having not read your post should be hit.

Yes it does, remember that mechanical loads are transmitted via the tires and axles.  The normal force applied to them will increase in direct proportion to propulsive force applied by the tires on the road.

At low speeds where aerodynamic drag is low, the normal force against the axle bearings is going to be dominated by the weight of the vehicle, at higher speeds, that normal force is going to increase as the force required to overcome aerodynamic resistance increases.

You are right, there is no velocity component to friction, but the cause of the normal force is directly linked to velocity.

ringersol: evaned: "... I wonder if you lose energy going faster too. Like, perhaps air drag increases. "

Who are you people? Are you farking serious?
Of course you're less efficient at high speeds than at optimal speeds.
But the author of the 'review' claimed he had the cruise control set at 45mph.
So we're not talking about stop-and-go vs 95mph.

Do you really think Manhattan stop-and-go is more efficient than 45mph on the highway, because of drag?

Actually that is exactly what we are arguing.

However I think most of the people in this thread arguing about efficiency realize that the reporter was full of crap, because he did not limp at 45mph for any amount of time.

Try to mentally decouple the argument about physicist from the article about the asshole reporter who faked an article.  Part of the problem we have, is that the physics of electrical vehicles is poorly understood.  People think they understand physics from their observations of the world.  Very frequently they are wrong.  That is why almost every 100 level physics course starts by explaining how a dropped ball moving horizontally and a dropped ball dropping with no horizontal component hit the ground at the same time.

ringersol: Do you really think Manhattan stop-and-go is more efficient than 45mph on the highway, because of drag?

If you have decent regenerative braking, I don't see why it's so hard to believe that it  isn't.

TheWindowLicker: "Actually that is exactly what we are arguing."

If that's the argument they want, I'm out.  Because there's a trivially true answer.
A few horsepower to counter drag at 45mph is nothing compared to the energy lost in start-and-stop traffic on a "Manhattan" scale. Not even after we account for energy recaptured by regenerative brakes.

And if we're being pedants, sure, I'll concede it's absolutely possible for a skilled driver in a dedicated vehicle to travel such a route using less energy than the Tesla Model S uses at 45mph.

But a naive driver in Manhattan stop and go in the Model S is going to eat more energy over 2 miles than that same driver, in that same car, at 45mph on the highway.

And, further, the physics of electrical vehicles aren't so poorly understood that we can't tell whether a detour through Manhattan would have a notable impact on range.
Tesla's sitting on a mountain of data and in this particular case could tell us fairly precisely how many additional miles could have been driven with the energy lost in Manhattan.

They could even spell out roughly how many miles could have been had under the false scenario the writer presented and under the true scenario of their highway travel.

evaned: "I don't see why it's so hard to believe that it isn't"

It's possible to construct a context where that's true.
But that context does not map to the situation at issue.

If you guys are headed off to hypothetical-land, I wish you the best of luck, but I was only ever talking about the situation at issue.

Man On A Mission: apparently Broder didn't do the necessary homework before testing out the car in the first place

I'd argue that if the objective to make an electric car that's as easy to drive as a gasoline-fueled car, then the driver shouldn't be faulted for assuming that there's no homework that needs to be done.

ringersol: If that's the argument they want, I'm out. Because there's a trivially true answer.
A few horsepower to counter drag at 45mph is nothing compared to the energy lost in start-and-stop traffic on a "Manhattan" scale. Not even after we account for energy recaptured by regenerative brakes.

And if we're being pedants, sure, I'll concede it's absolutely possible for a skilled driver in a dedicated vehicle to travel such a route using less energy than the Tesla Model S uses at 45mph.

But a naive driver in Manhattan stop and go in the Model S is going to eat more energy over 2 miles than that same driver, in that same car, at 45mph on the highway.

You may be right, but I don't think the answer is as trivial as you want it to be.  I don't know any of the constants involved, but for a wild ass guess I would be willing to give even odds that the break even point is at or below 60 mph (the speed the reporter actually averaged) and I am quite convinced that break even point is below the reporters 80+mph maximum speed.

A purely electric drive train can be incredibly efficient.  The assumptions you are making to make your "trivial" solution are all developed by your experiences with internal combustion power trains.  These are systems that are extremely inefficient at city driving.  IC systems are especially inefficient when compared to direct drive electric motors.  Just compare the torque/power curves of an IC motor and an electric motor.

The Tesla S has a very low drag coefficient; I am not sure where aerodynamic forces start to dominate.  I would go so far as to say you are probably right that it is above 45mph, but I don't think it is far enough that you should be comfortable assuming it is a trivial comparison.

Atreyou40: gweilo8888: ringersol: But does that sound remotely plausible?  A maker of electric cars saying "Adding stop-and-go traffic to your trip will *improve* your total range"?
The only person claiming they got that advice is the author whose story was just gutted by the actual trip data.
Are we really supposed to take him at his word on this?

Frankly, yes, it does. When was the last time you spoke to a call center and got a *knowledgeable* employee? And when was the last time the call center staff member had a salary that would let them drive a US$100,000 car, to give them any personal experience to counter their lousy intuition and guesswork as to how the product operates?

So yes, it sounds more than plausible. Most likely the support droid was asked a question that wasn't covered by the handbook that is the only "knowledge" they have of a vehicle they've probably never even seen in person, or they simply forgot the handbook answer, and either way incorrect info was fed out.

You're both dumbasses. It's called "regenerative braking" an it's been around since the first hybrids and the idea is that a car in motion has some measurable inertia and to use the brakes as a capture device for that energy. I'm no physicist, and I have my doubts about the efficiency of such a thing given our current technology, but I have no doubt it's possible and even beneficial and can extend the range of an electric car by a couple miles, if not more. Here, why don't you go learn something:

http://en.wikipedia.org/wiki/Regenerative_brake
http://auto.howstuffworks.com/auto-parts/brakes/brake-types/regenera ti ve-braking.htm
http://green.autoblog.com/2009/04/16/greenlings-what-is-regenerative -b raking-and-what-types-are-ther/

There's even a youtube video for the spectacularly ignorant:

http://www.youtube.com/watch?v=y8jRAwIzPTM

Oh what the hell, here's more links:

http://www.wisegeek.org/what-is-regenerative-braking.htm
http://www.fueleconomy.gov/feg/hybridanimation/fullhybrid/fullhybri ...

Here's the premise you're missing in as little math as possible and as simple as possible.

10-9+1=2    Final - Initial = -8 (Regenerative braking)
10-9=1        Final - Initial = -9 (Non-regenerative braking)
10-0=10      Final - Initial = 0 (No braking at all, ignoring friction, drag etc)

Regenerative braking reduces energy lost, but braking still loses energy period.
Leave physics to the people who understand it.

ringersol: If you guys are headed off to hypothetical-land, I wish you the best of luck, but I was only ever talking about the situation at issue.

So I got all curious now, (sorry if I won't leave you alone) and I wanted to figure out what some actual numbers are.

From http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=32557 the Tesla S gets 88MPGe City and 90 MPGe Highway.

From the EPA testing details page: http://www.fueleconomy.gov/feg/fe_test_schedules.shtml you can see that the average speed of the highway test is 48mph, and the average speed of the city test is 21mph.  The City course has 23 stops over 11 miles in a time of about 32 min.  I have not driven in Manhattan, but I have a feeling that there is a whole lot more starting and stopping.  However, the city course also gets up to 56mph; a speed I am confident is not driven frequently in downtown Manhattan.

Assuming the Epa tests are relatively balanced, it looks like the Tesla S is more efficient in stop/start traffic, than it is at some average speed slightly above 48mph -lets guess 50- so I will concede that you are right about your guess with 45mph.  I will also say that you are nowhere near as blatantly right as you thought you were.

MadCat: I'm sure that's true if you're looking for decimal point accuracy. For the majority of us it's enough that our speedometers match the automated police radar traps that display "current speed"

I'm a cab driver and light duty mechanic, I've driven hundreds of different vehicles over the last couple months and I have yet to find one that failed this test on stock wheels and properly inflated tires. When they don't match it's always been due to improper replacement tire selection, or low tire pressure.

Yeah, no. If you find them matching that consistently, then you're not testing in an accurate manner. Sorry, but that's simply the only option, because it is not difficult to find new cars that fail the test.

I have driven many myself, mostly with a reading that's 3-5mph faster than you're actually doing, and occasionally (eg. the now-discontinued Mitsubishi Diamante) the rarer car that reads 3-5mph slower than you're doing. Only a couple have come within 1mph of accurate, and I have never yet seen a vehicle that precisely nails it at 55mph. And that is with tires inflated precisely (checked using multiple different, accurate pressure monitors) and using stock wheels / tires.

Broom: If you say so. I've never toured a parking lot that many times in my life for a spot; can't remember the last time I even did more than a full circuit - including when I lived near Milford CT, which is apparently part of the route.

I can't comment on the locale; I've never been to CT. I've been to plenty of other places where it would be believable, and to places where even half an hour's circling might not net you a space, but I doubt anywhere in the US except perhaps New York or LA is the latter.

gweilo8888: horsepocket: You need to get better cars. Seriously, you really need to buy better cars. I've owned 11 cars over the course of my life, ranging from a used 86 Cutlas to a new BMW, and never has the speedometer been off by more than 2mph when compared to radar results. The speedometer is usually dead on, which always surprises me.

Changing out wheel and tire sizes can have an effect on your speedometer reading, but I'm guessing a stock from the factory test car will have a speedometer off by more than 1mph.

Try paying more attention. The amount by which the speedo differs from the real speed typically varies significantly depending on the speed you're driving at. That's why I cited "at 55 mph", because that's what *I* typically pay most attention to, since that's the speed I most often drive at.

And I've driven plenty of cars, including American, Japanese, and European. Not sports cars, but more than a few expensive sedans. (And a couple of cheap ones, as well; interestingly one of the cheapest was one of the most accurate.)

Very few have been within 2-3mph, and I've yet to find a single car that was 100% accurate at 55mph, let alone at all speeds. And that's on stock rubber. (I never, ever put a different size wheel/tire on a car than it left the factory with.)

The speedometer in our 10 year old Hyundai---not exactly a high-end car---is consistently about 2mph under the speed reported by our GPS.  I think I'd be very annoyed if it were off any more than that.

Woah woah woah!!!

I've been assured by multiple farkers multiple times that the media is NOT BIASED.

Given the number of comments, I poked in looking for boobies. Leaving drained.

gweilo8888: MadCat: I'm sure that's true if you're looking for decimal point accuracy. For the majority of us it's enough that our speedometers match the automated police radar traps that display "current speed"

I'm a cab driver and light duty mechanic, I've driven hundreds of different vehicles over the last couple months and I have yet to find one that failed this test on stock wheels and properly inflated tires. When they don't match it's always been due to improper replacement tire selection, or low tire pressure.

Yeah, no. If you find them matching that consistently, then you're not testing in an accurate manner. Sorry, but that's simply the only option, because it is not difficult to find new cars that fail the test.

I have driven many myself, mostly with a reading that's 3-5mph faster than you're actually doing, and occasionally (eg. the now-discontinued Mitsubishi Diamante) the rarer car that reads 3-5mph slower than you're doing. Only a couple have come within 1mph of accurate, and I have never yet seen a vehicle that precisely nails it at 55mph. And that is with tires inflated precisely (checked using multiple different, accurate pressure monitors) and using stock wheels / tires.

I've had the same experience. My car consistently reads 2.5mph faster than I'm actually going. Tire pressure, size are all according the manufacturer and this happens even with brand new tires that aren't worn down. GPS and those radars at the side of the road show my true speed.

I compensate for this when I go my typical 8 mph over the speed limit.

FizixJunkee: The speedometer in our 10 year old Hyundai---not exactly a high-end car---is consistently about 2mph under the speed reported by our GPS.  I think I'd be very annoyed if it were off any more than that.

Interestingly, the most accurate I can recall was in a cheap late 90s Kia, long since scrapped I'm sure. (It *was* a Kia, it was horribly built even when new.) ;-) That was only off by 1-2 mph. The Koreans must be big on accuracy.

God forbid you pay a fortune for a car and just expect it to get you somewhere without any trouble.

Man, a lot of you guys seem to have a fetish for testing your spedos.

Call me when I can get one for $25k, until then it's just another toy for the wealthy.

Tesla owners and fans are the worst sort of evangelist for "their" product and Elon Musk is probably the worst of them all. I have no doubt he'd falsify data for the "cause" because he's a true believer. This is the same kind of behavior that leads to priests abusing children and not being reported.

Ask yourself, who has the greater motive to lie:

1. A gabillionaire struggling to create credibility for a corporation that took half a billion in federal alt-energy money, and sells a beautiful electric car for twice what most Americans make in a year.

2. Or a long-time reporter for the best newspaper in the world, a guy who has never had his credibility seriously questioned, who has written on the environment for decades.

Ask yourself whether it's possible that the data is somehow screwed up -- heaven knows I could produce a chart right now proving that you are actually a cat.

Seriously. Elon Musk isn't gonna give you a ride in his rocket because you White Knight him on Fark or Reddit.

Popcorn Johnny: Both have obvious reasons to lie. Screw it, I'm going to watch Harlem Shake videos.

i think i'm officially old. i have no idea why harlem shake videos are popular. i've watched a few, and wasn't amused at all, and i am very easily amused

 i just don't get it

animal color: Ask yourself, who has the greater motive to lie:

1. A gabillionaire struggling to create credibility for a corporation that took half a billion in federal alt-energy money, and sells a beautiful electric car for twice what most Americans make in a year.

2. Or a long-time reporter for the best newspaper in the world, a guy who has never had his credibility seriously questioned, who has written on the environment for decades.

Ask yourself whether it's possible that the data is somehow screwed up -- heaven knows I could produce a chart right now proving that you are actually a cat.

Seriously. Elon Musk isn't gonna give you a ride in his rocket because you White Knight him on Fark or Reddit.

I'm also not sure I'll jump on the bandwagon that he purposefully created the outcome, but I do think he didn't drive the car as it was meant to be driven. The car has been reviewed by quite a few organizations, many of which you can view on youtube, and none of them had issues when they treated it like an EV.

So, what we have here is a technological misunderstanding, or to say it another way...a journalist who failed to do his research.

Here's the NYT rebuttal:  http://wheels.blogs.nytimes.com/2013/02/14/that-tesla-data-what-it-sa y s-and-what-it-doesnt/

BackwardsHatClub: Tesla owners and fans are the worst sort of evangelist for "their" product and Elon Musk is probably the worst of them all. I have no doubt he'd falsify data for the "cause" because he's a true believer. This is the same kind of behavior that leads to priests abusing children and not being reported.

You do realize that one is owned by the other, right?

/ 1/10, you got me.

http://money.cnn.com/2013/02/15/autos/tesla-model-s/index.html

CNN Money redid the trip in a model-S. The Verdict? "With a full battery, there was no need -- none at all -- to nurse the car's battery."

Also, he Tweeted:

Um... Not that hard. At @TeslaMotors Milford SuperCharger. Been leadfootin' last 20 miles

Seems Broder has some 'Splaining to do.

The WindowLicker: "I have not driven in Manhattan, but I have a feeling that there is a whole lot more starting and stopping."

And this is where our entire divergence happened.  Because driving in Manhattan isn't even like a *pessimistic* EPA city route.  It's like a worst-case.  Because it's not 25-35, and neither is it a stand-still.  It's 20-ish city blocks per mile in NYC and if you made it 40 blocks with 20 stops through Manhattan, it would have to be midnight on Christmas.  Further, these aren't idealized starts and stops.  These aren't slow rolls off the line.  This is quick acceleration to keep from getting cut off.  Quick stops to avoid constant obstacles.  And regenerative braking also doesn't work nearly as well when people aren't coasting to a stop.

If we were talking about 2 miles through a normal city or US metropolitan/suburban sprawl, I would agree the detour was a relative non-issue for a car like the Tesla S.  And it may well be debatable whether it was notably less efficient than the highway at 45 mph.  I agree it certainly wouldn't be an easy call.  But in the case we're talking about, yeah, it is an easy call.  It's as easy as saying a teenager in Daddy's sportscar isn't coming anywhere close to the EPA fuel efficiency numbers.

This is how the article reduces to me.

"I knew it was 200 miles to the next charge station and I had 200 miles' worth of power in the battery.  I took a detour through Manhattan, so my trip was 202 miles instead of 200.  I can't figure out why I didn't make it!"

Lsherm: Johnsnownw: animal color: Ask yourself, who has the greater motive to lie:

1. A gabillionaire struggling to create credibility for a corporation that took half a billion in federal alt-energy money, and sells a beautiful electric car for twice what most Americans make in a year.

2. Or a long-time reporter for the best newspaper in the world, a guy who has never had his credibility seriously questioned, who has written on the environment for decades.

Ask yourself whether it's possible that the data is somehow screwed up -- heaven knows I could produce a chart right now proving that you are actually a cat.

Seriously. Elon Musk isn't gonna give you a ride in his rocket because you White Knight him on Fark or Reddit.

I'm also not sure I'll jump on the bandwagon that he purposefully created the outcome, but I do think he didn't drive the car as it was meant to be driven. The car has been reviewed by quite a few organizations, many of which you can view on youtube, and none of them had issues when they treated it like an EV.

So, what we have here is a technological misunderstanding, or to say it another way...a journalist who failed to do his research.

The problem here is that he wasn't driving the car as "it was meant to be driven" - he started out with the intention of driving the car like a normal person along the most electric-friendly 500 mile route that exists in the US right now.  He called Tesla numerous times along the way to check about the battery life, and they repeatedly told him either the wrong information or they had too much faith in the car.

Considering most people aren't calling Tesla for advice while driving their cars, it's still up in the air.

CNN who did the exact same route while speeding part of the way and had absolutely no problems demonstrates the issue with the story is this particular reporter.  You may argue Tesla is fudging the data but you can't argue CNN is in bed with Tesla when they put out their own story confirming its absolutely  possible and easy to do without restricting the ride one bit.