A Camry will do 4mph in a foot, fast cars do 5-6mph. This is worth the read for more background: 2017 Tesla Model S P100D First Test: A New Record - 0-60 MPH in 2.28 Seconds! - Motor Trend
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200 kWh Roadster Pack: How is Tesla Pulling This Off?
- Thread starter jackbowers
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- Batteries Roadster 2020
Very fast EV travels first foot in 0.2195 s accelerating to 6.213 mph. I assumed constant acceleration from 0 to 60 mph. Acceleration could be faster during first foot.
Found this before edit time expired. Everything (or more) you want to know about 1 foot roll-out:
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Thanks for all this information. It all makes perfect sense. And yet it rubs me the wrong way. Claiming 2.3 seconds zero to sixty when it's actually six and a half to sixty just seems wrong. The cool part is that with the top-accelerating Teslas, the limiting factor is the tire grip, not the motors. Though for me, the coolest part is not the outrageous acceleration, it's the fact that they don't use any gasoline, and if you have solar panels on your roof or a wind charger in your yard, you are running you car on free energy. (Mine runs on hydro.)
To be fair, I think Tesla was publishing 0-60 on their website and reviewers started publishing 1 ft roll out times. The Model X 2.9 and Model S 2.5 are both 0-60 I believe.
I don't like system, but I think Tesla and Motortrend are using 1 foot roll-out in all numbers.
I get the feeling that people are too fixated on current economical battery technology. Who's to say that Tesla doesn't already have a far better battery, just one that is cost prohibitive to use in mass market cars? I would not be surprised if they already have better technology, just that it is only cost effective in a $200,000+ supercar.
"Better" is a very subjective term. "Better" for me means greater energy density, for a high range:weight ratio. Better also means affordable for me. For someone who wants a supercar, "better" would mean able to deliver a lot of power quickly. There are always trade-offs, and "better" means different things to different people.
The fact that the New Roadster has both fast acceleration and very long range suggests that there's nothing special about the battery technology: They needed a lot of batteries to deliver the needed power, and so they got a lot of range as a side effect.
Tesla quotes Model S P100D to do 0-60 in 2.5 seconds. Motor trend and others who are timing with 1 foot rollout are less than that such as Motor Trend's 2.3 seconds. That youtube video basically verifies Tesla quoted 0-60 of 2.5 seconds.
Tesla's quarter mile numbers and other publications who are using drag strips for timing and ET are using 1 foot rollouts.
e-FTW
New electron smell
It would be easy to get rid of the one foot rollout thing: have another light beam an inch forward from the first one, and have that trigger timing, instead of relying on the tire leaving the first beam. It would be a one inch rollout, well within any margin of error. Imho
From a link in the Investor’s General Discussion Thread, Jerome Gullen just stated that the target for the semi is to have the same payload capacity as a diesel semi. This would seem to indicate they have a battery breakthrough in gravimetric energy density. Unless he meant when using a specialized lightweight Tesla trailer?
Then I will clarify to mean that they may have better energy density batteries, but currently at a higher cost/kwh. That seems like a lot of 2170 cells to stuff into such a small frame. As always, I could be wrong.
There's good bloody reason for our pessimism.
Wikipedia has not changed it's estimate for max Lithium-ion at 265 Wh/kg for years.
Battery University is a similar story.
Elon Musk's claims about improvements were quite close to industry max energy density at the time.
Model 3 cells show a similar energy density to the S cells when taking into account a realistic weight of 65-70 grams given the 2170's volume over the 18650's volume, and the 18650 is 47.5-49.5 grams.
Not to mention the absolute horde of two-bit peddlers claiming "ground-breaking proprietary technology" of some sort or the other and completely failing to prove it when the big players are actually relatively open about their chemistry.
And who can forget all those research articles that mention a genuine breakthrough in one or two or more properties, only to hide well out of sight, a few important and often inherent small prints, usually such as inherent manufacturing cost, lifetime, or efficiency.
All previous speculation I saw was that there would be a substantial weight gain for any substantial battery pack vs. a diesel drivetrain. To have equivalent cargo capacity, the semi cannot weigh more than a traditional semi.
I think what you are saying is that the maximum gross vehicle weight is 80,000 pounds, and that includes the tractor and its engine + fuel or motor + battery pack. Put swap out the diesel stuff for motor and batteries, and the difference in weight has to come out of the cargo.
Perhaps so, but is it really that significant a loss in net cargo, compared to the net improvement in operating efficiency?
Link I posted above explains this: Modern hardware does measure real 0 to 60 time. 1 foot roll-out time is used for compatibility.
I believe Tesla has 10%-50% better energy density chemistry. It will come to mass production slowly, because they want to avoid very costly mistake.
Don't forget the cumulative weight of trillions of electrons on a fully charged battery. An often ignored and overlooked component.
As we speak, Mr. Whalman just published a devastating article on that topic in SA.
"Trillions of heavy electrons will sink Tesla's truck, the mordern day Titanic"
While GM engineers have worked hard to produce leaner, lighter powerful electrons, there are no such patents for Tesla.
As we speak, Mr. Whalman just published a devastating article on that topic in SA.
"Trillions of heavy electrons will sink Tesla's truck, the mordern day Titanic"
While GM engineers have worked hard to produce leaner, lighter powerful electrons, there are no such patents for Tesla.
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