Gen III Range & Pricing Speculation

[stopcrazypp]

Rather than guessing, it's instructive to look at the best in the industry right now, the Fit EV at 118MPGe vs Model S 89MPGe. That's 32.5% better. That includes charging losses.

If we look at pure battery range, it's 82 miles on 20kWh = 4.1 mi/kWh. Model S is 265mi on 85kWh = 3.1mi/kWh. That's 32.3% better.

I'm not sure how much more can be squeezed out. Keep in mind, the Fit EV uses a battery that likely has much lower internal resistance than the Model S's. Also in terms of aerodynamics, smaller cars in the compact class tend to be taller and shorter in length. This makes it actually harder to get the same Cd of the Model S. In terms of weight, the Fit EV uses a steel chassis, much like the Gen III likely will (which will make it harder for weight reduction).

In summary, for the Model S vs the Fit EV you get about 32.5% better efficiency/range and from 30% less weight and 16.5% more CdA (rectangular), details below:

The Fit EV is 3252lbs vs 4,647.3lbs for the Model S. 1395.3lb difference (exactly 30% difference).

Cd of Fit EV is ~0.29 (14% better than the 0.34 of the gas Fit).
Frontal Area (just a rough rectangle, not actual) = 67.7"W * 62.2"H = 4210.94 square inches.
CdA (rectangle) = 1221.2 square inches

Cd of Model S is 0.24.
Frontal Area = 77.3"W * 56.5"H = 4367.45 square inches.
CdA (rectangle) = 1048.2 square inches

So Fit has a 16.5% higher CdA (rectangle).

http://automobiles.honda.com/fit-ev/specifications.aspx
http://www.teslamotors.com/models/specs

[JRP3]

The Fit battery does have lower internal resistance and can safely use a larger portion of it's capacity, but it also has lower energy density, so it probably is heavier per kWh.

[WhiteKnight]

Cd of Fit EV is ~0.29 (14% better than the 0.34 of the gas Fit).
Frontal Area (just a rough rectangle, not actual) = 67.7"W * 62.2"H = 4210.94 square inches.
CdA (rectangle) = 1221.2 square inches

Cd of Model S is 0.24.
Frontal Area = 77.3"W * 56.5"H = 4367.45 square inches.
CdA (rectangle) = 1048.2 square inches

So Fit has a 16.5% lower CdA.

The number for the Model S looks to be less than the Fit not vice versa. 1048.2 versus 1221.2.

[vfx]

Tesla was way off on their weigh goals. I would think they would rein that in on the next car giving better range.

[Doug_G]

Tesla was way off on their weigh goals. I would think they would rein that in on the next car giving better range.

As I've mentioned elsewhere, I think the overriding desire to have an across-the-board 5-star crash rating led to extra weight. All engineering is a compromise, and something has to give... more mass = more robust.

[stopcrazypp]

The number for the Model S looks to be less than the Fit not vice versa. 1048.2 versus 1221.2.

You are right, edited my original post for correctness. I guess I really have to do an actual CdA analysis for good numbers, since the rectangle is too rough (apparently the Fit EV is 2.2 inches higher than the normal Fit from a higher ride height).

And it's hard to quantify what's the effect purely from weight, since the the Leaf is lighter than the Focus EV, but the Focus is more efficient. Probably looking the differences between a mid-sized to full-sized sedan vs a compact (ideally using the same engine) might show the pure effect of weight and CdA better.

[zachster]

One of the most interesting bits from the Q2 conference call was about the Gen 3 battery chemistry (very last question of the Q&A):

Jesse Pichel – Jefferies

I guess it not quite as exotic as picking up your Mercedes from Stuttgart, but I guess you can give them a burger and send them on their way. But you made an interesting comment, Elon, about battery pack replacements allowing the car a better range versus today. You said this before. When can we expect the next battery chemistry improvement, and what’s your roadmap for that?

Elon Musk

I think it’s probably with the Gen III that we’ll see a change in the fundamental chemistry, as we did with Roadster. With Roadster we went from a cobalt cathode to a nickel-cobalt aluminum cathode, and effectively a few percentage increase - roughly [50%] increase in both gravimetric and volumetric [energy density]. And then also a drop in cost, because of the much lower cobalt content. I can’t comment on the specifics of some of the technologies that I’m aware of, because of confidentiality agreements, but I can say I’m highly optimistic about seeing substantial reductions in cost per kilowatt hour in the three to four year time frame.

I'm reading this as Tesla plans to transition ALL it's battery packs to the next chemistry advance. With reservations on Model S being a year out and Model X production being 1 and 1/2...I think we're not too far from the point it would make sense to postpone a reservation to take grab the next battery chemistry.

Then again, with this attitude, you would never be satisfied with your electronics purchase. Thoughts?

[stopcrazypp]

One of the most interesting bits from the Q2 conference call was about the Gen 3 battery chemistry (very last question of the Q&A):



I'm reading this as Tesla plans to transition ALL it's battery packs to the next chemistry advance. With reservations on Model S being a year out and Model X production being 1 and 1/2...I think we're not too far from the point it would make sense to postpone a reservation to take grab the next battery chemistry.

Then again, with this attitude, you would never be satisfied with your electronics purchase. Thoughts?

With that attitude, you will have to keep waiting because by the time the next chemistry advance is in production, the next one after that would be in planning phases in 3-4 years.

It does make sense however to wait out the first generation of a product for all the bugs to be worked out. Usually the second generation would be a lot more polished.

[vfx]

... phases in 3-4 years.

It does make sense however to wait out the first generation of a product for all the bugs to be worked out. Usually the second generation would be a lot more polished.

Same think here though. Is the X a second generation? With AWD and crazy doors maybe not. Is the Bluegenlll 2nd generation? Smaller all new form factor, new battery chemistry, Elon surprises, maybe not. Roadster ll? High power, handling and on and on and on...

[stopcrazypp]

Same think here though. Is the X a second generation? With AWD and crazy doors maybe not. Is the Bluegenlll 2nd generation? Smaller all new form factor, new battery chemistry, Elon surprises, maybe not. Roadster ll? High power, handling and on and on and on...

I'm thinking more in the lines of the next model year of the Model S. Not something that is necessarily completely new. The Model X is quite close given it shares the same platform, but you make a good point about the doors and AWD.

Roadster II is essentially an entirely new product, even though it keeps the same name. I'm thinking something more in the lines of Roadster 2.0 and 2.5, which are a relatively minor refinement of a 1st gen product.

The general idea is you have a year or so where consumers have evaluated the product and any early bugs and kinks would have been worked out by then (or at least discovered).