concerns about the 40kWh pack

[Rifleman]

I still don't see how that's rude, but understood.

What I meant was that the guesstimations are a bit premature and paranoid, not the author.

No offense taken. I think with the information we have right now (the only 2 data points we have for vehicles with a battery of this size are the Rav4 and to a lesser extent the Coda) the estimates are as accurate as can be made. When more data becomes available, I will definatelly revise them. I think we are all hoping that the Tesla secret sauce results in a 40 kWh with 40% more range than the other 40kWh vehicles on the market, but without data, assuming anything else would be premature.

[crzyskl]

I haven't owned alot of cars, but the ones I have owned, never perform as the EPA says they will. I put very little stock into the EPA testing and how it compares to actual people driving the car. My current Prius since ownership (55,000 miles) gets 58mpg (above EPA), but our 2011 Hyundai Tucson gets 24mpg including alot of open highway driving (below EPA). Correct me if I am wrong, but the indication I get from most Roadster owners on this forum is that the 245 miles range is pretty accurate (again, I could be wrong), sometimes a little more sometimes a little less.

It does make sense for you to wait so you can double check to ease your range anxiety, but it sounds like your CURRENT concern is with how the EPA says its going to perform and hopefully your range anxiety will be eased when real drivers start driving the cars in real world conditions.

Quick question for anyone who knows: Is the current RAV4 EV the same battery technology (chemistry, etc) that is going into the model S? That might also have a difference in the expected range. I am just a Quality engineer, not a real engineer.

[mnx]

Tesla has rated it at 160miles @ 55mph. Just keep your speed as close to 55 as possible on the highway and you'll have no problem.

No offense taken. I think with the information we have right now (the only 2 data points we have for vehicles with a battery of this size are the Rav4 and to a lesser extent the Coda) the estimates are as accurate as can be made. When more data becomes available, I will definatelly revise them. I think we are all hoping that the Tesla secret sauce results in a 40 kWh with 40% more range than the other 40kWh vehicles on the market, but without data, assuming anything else would be premature.

[qwk]

We do not know what size of pack and what cells Rav uses. If the model S performs like the roadster(there is no indication why it wouldn't), then it will be very possible to get 160 miles in range mode.

[ckessel]

We do not know what size of pack and what cells Rav uses.

The press release mentioned 41.8 kWh as I recall for the Rav4EV.

[Larry Chanin]

I fully agree the conclusion that the Model S will only do a little bit better is questionable (I hope my concerns are completely unfounded on this one). Right now, the Rav4 is advertising a range that is about 40% less than the Model S, with what is essentially the same size battery. I am not an automotive engineer, and I cannot even begin to determine if the aerodynamic and weights differences between the two vehicles should reflect that large of a difference. But the second conclusion that is the model S only has a 115 mile range, and charging in standard mode results in 20 % (top 10% and bottom 10%) not being used, the 92 mile range figure is pretty solid (unless I am worse at math than I thought).

I don't know whether you had a chance to review the links I provided up thread, but here's the meat of my first link.

An excerpt of Tesla's 10-K Annual Report:

We plan to offer Model S with a variety of battery pack options—40 kWh, 60 kWh and 85 kWh—which we estimate will offer a range on a single charge of 160 miles, 230 miles, and 300 miles, respectively, while traveling at a steady speed of 55 miles per hour. The EPA’s new fuel economy requirements will require us to label Model S utilizing new and different energy efficiency testing methodologies. These methodologies differ from the one we have used to estimate the range of the vehicles at a steady speed of 55 miles per hour and could reduce the range reported on the required labeling of our vehicles by up to 30% as compared to our current estimates.

When you do the math,

EPA 5-cycle range = .7 x 160 = 112 miles in range mode.

has any word been given if the 100 mile range on the Rav4 is in range mode or standard mode? I suppose this would have a big impact of my guesstimates.

I don't know the answer, but my guess is that Toyota did similar math as above, using range mode, it came out a little above 100 miles and they rounded down.

Larry

[Robert.Boston]

My summary of the thread: wait and see.

We don't know how conservative Tesla is being stating the 100 mile range; we don't know the Model S range in actual driving conditions. By the end of the summer, I expect that we'll have many more data points about the second of these, which is what you really care about.

My guess is that careful driving will take the 40kWh pack 160 miles. If you drive 75 mph along I-71, though, you'll do worse.

[spatterso911]

Then there is also the question of total range (full charge) and ideal range.

[Larry Chanin]

My summary of the thread: wait and see.

We don't know how conservative Tesla is being stating the 100 mile range; we don't know the Model S range in actual driving conditions. By the end of the summer, I expect that we'll have many more data points about the second of these, which is what you really care about.

My guess is that careful driving will take the 40kWh pack 160 miles. If you drive 75 mph along I-71, though, you'll do worse.

Hi Robert,

Obviously, folks always can wait and see, but we can also make reasonable guesses as what the EPA range will be.

We know that Tesla is advertising a 160 mile range driving at a constant 55 mph in range mode. We have found in the case of the Roadster the range at 55 mph was in close agreement with the EPA 2-cycle test. We know that EPA has a guideline in which they will mulitply the 2-cycle range by .7 to arrive at the new 5-cycle range. So if the Model S' advertised range at 55 mph is also close to the EPA 2-cycle range, then we may have a good approximation of what the new EPA range will be by multiplying the advertised range by .7. (Refer to the second link my earlier posting.)

The new EPA 5-cycle test is supposed to offer a more realistic range in typical driving conditions and it was adopted to help consumers in arriving at reasonable expectations. Sure people can do better than the EPA range number if they drive slower or less aggressively. The question is will they?

Larry

[ElSupreme]

Sure people can do better than the EPA range number if they drive slower or less aggressively. The question is will they?

Slower and less aggressively than a F1 driver? Sure.
Slower and less aggressively than 98% of the people on the road? Probably not!

Then again I am banking on a range (range mode) of 112 miles. And a range (standard mode) of 89 miles. With my normal driving habits, (~70-30 highway/city). And when I expect to need to drive further I have been known to be able to drive 55mph.

I personally think the EPA range will be about 130miles, which will correspond to cruising at about 65-70mph. Based on numerous rough number crunches looking at a variety of energy consumption graphs.

My real hope is that the 40kWh Model S can cruise at 75mph over 100 miles on a mild summer day.