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300 mi now 265 mi after EPA test?

300 mi now 265 mi after EPA test?

In a recent Telsa newsletter I received, it referred to an article http://www.insideline.com/tesla/model-s/tesla-moves-up-model-s-launch-to... that stated after EPA tested the 85kWh model, they rated it as having 265mile range NOT the 300 miles that Telsa has always stated. This may be due in part to the 5 cycle test that they utilized instead of the 2 cycle test used in the past which yielded 320miles! I do not understand what these tests are nor the difference. EPA’s new 265mi result is only 20mi further than the Roadster’s 245mi range which has been battery technology which has been out for years.

I do know that when I had made the decision to upgrade from the base 40kWh model to the 85kWh model and pay $20,000 additional to do this, it was for the sole purpose to obtain 300 miles at 55mph as Telsa has told everyone.

Questions:
1. So if I take my fully charged 85kWh S model on the interstate at a constant 55mph no AC or other power drains flat terrain etc, will my range be 300miles or 265miles?
Are the 230 and 160mile versions also now less than stated per EPA testing?

2. I realize if I go 70mph, my range may be expected to be 70% of the official stated range of: 300 or is it now 265miles?

3. If it is now 265mi, will Telsa add a small supplemental trunk battery to compensate for the now EPA missing 35miles+265=300mi ? This would help deliver on the promise of a 300mile electric car.

I hope Telsa can clarify and reassure us about this battery range issue since delivery is ahead of schedule, now June 22, 2012! It should be noted that I am very proud of Telsa overall and all of it’s accomplishments and innovations that Elon Musk and his engineering team have given leadership to and have been creative in solving issues such as this. Thanks.

Amos | May 22, 2012

Actually, the update I received from Tesla today pointed to a Tesla blog post which makes things petty clear. I'm not sure how you wound up on the Edmunds site, but they appear to have done a poor job of explaining apples and oranges.

http://www.teslamotors.com/node/18774

Soflauthor | May 22, 2012

This article:

http://www.greenercars.org/guide_epameas.htm

provides a good summary of EPA testing.

The 5-cycle test that the EPA uses does result in lower EPA estimated range than the previous 2-cycle test, but the range you'd get on the highway under the conditions you note will be far closer to 300 miles than 265. At the end of the day, the 5-cycle EPA range is a reference metric, used to compare one car to another. It is not an absolute indication of your range under normal driving conditions because those will vary from driver to driver and locale to locale.

Rod and Barbara | May 22, 2012

GeorgeA, the answer to your first question is that the 85 kWh Model S will go about 308 miles at 55 MPH per the graph at http://www.teslamotors.com/sites/default/files/graph1.png.

MarkV | May 22, 2012

George, As they say the devil is in the details. The original EPA 2-cylcle test uses certain standard conditions (55% city stop and go, 45% highway with a maximum speed of 60 mph, and a comfortable 75 deg F temperature that does not require heating or cooling). With these conditions the Model S out performs every other car subjected to the same test and achieved a range of 300 miles. That range has not changed for those conditions. Along comes the 5-cycle test. Now the EPA has added cold weather and hot weather condition that require heating or cooling of the interior both of which will consume energy. They also increased the highway speed to 80 mph which will consume more energy as well. Just the 33% change in speed requires 77% more energy for the time driven at 80 mph because the wind resistance increases by the square of the difference in speed. Consequently the 5-cycle range estimates for the Model S are lower. Well, any of the other cars to which the Model S is compared will also have a lower range under the 5-cycle conditions than what was reported previously. Rest assured, you will be able to achieve a 300 mile range if you so choose. Everything is relative, and when using equal comparison methods, the Model S is simply the best car to come along to date. Hopefully we will all be proud owners soon.

Sudre_ | May 22, 2012

My answer to your question is next year they will come up with ANOTHER test that will decrease BEV distance even more.

Find one of the watt per mile charts floating around here and just calculate the distance at whatever speed you want to go.
For example
at 70 MPH the motor draws 327 watts per mile (got that from a different post) so an 85kW battery will go 259 miles at that speed without the A/C or head lights.

at 60 MPH the motor draws 275 watts per mile so an 85kW battery will go 309 miles at that speed without the A/C or head lights.

I did not subtract the 10% or 20% that would be recommended to increase battery life.

GeorgeA | May 22, 2012

Thanks everyone for that clarification on range and EPA tests. According to the excellent links you provided, the new 5 cycle EPA test combines city and highway driving under a variety of conditions which basically lowers overall mileage number.

One could debate the merits of this 5 cycle test, but the resultant lower range numbers the public will see don't seem to promote green technology which is ironic to EPA's purpose to protect the environment, which S Model will do. Telsa should counter by making sure prospective buyers know that S Model's range is not limited to but can exceed 300+ miles at lower than 55mph speeds as revealed by the graph.

I will need the AC often living in Orlando,FL. It rains often in the summer so wipers and headlights needed and of course some music is always nice. Like many 85kWh owners, I just wanted some reassurance that I could take some trips without road range fear. Miami Beach or Tallahassee at 240 miles away will be obtainable.
I like the idea of an emergency trunk battery with 25 miles just in case. Or this could be a future option.

stephen.kamichik | May 22, 2012

A future option will be a 500 mile battery pack.

Timo | May 22, 2012

I think the bad test to BEV in 5 stage test is the one which involves rapid accelerations and decelerations which go over the regen ability of the car so that you lose the energy there just like ICE car. All others BEV should give quite good results. If you think ahead driving in city you rarely need to do that so it's actually something that makes real world results better than EPA test shows.

Volker.Berlin | May 23, 2012

One could debate the merits of this 5 cycle test, but the resultant lower range numbers the public will see don't seem to promote green technology which is ironic to EPA's purpose to protect the environment (GeorgeA)

Not sure. What is worse: A Nissan Leaf announced with 100 miles range that makes it to the headlines b/c 70 miles is more realistic? Or a Model S with 265 miles "sticker range" that can be driven beyond 300 miles if need be and circumstances are favorable?

If you want to express range in a single number, it doesn't get more accurate than this. When going full throttle end-to-end, the 80kWh battery will be empty after less than 100 miles, and when driven really carefully (on a nice day with windows up etc.), even 400 miles are likely achievable. As we all know, driving habits and requirements vary significantly between individuals. The EPA (and other organizations) are still in the process of figuring out a way to present BEV range in a single number that bears some relevance for the "average" user. In this regard, the 5-cycle test is an improvement over the 2-cycle test IMO.

If you think ahead driving in city you rarely need to do that so it's actually something that makes real world results better than EPA test shows. (Timo)

Exactly, and I think that is a positive contribution to green technology publicity. Prospective buyers will be much more confident if it is clear that the published ranges are actually relevant to their daily driving. Bigger number are good for bold statements, but actually contribute to the FUD around BEVs.

What we really want, of course, is 500 miles by the EPA 5-cycle test! :-)

Volker.Berlin | May 23, 2012

Correction: The large battery option for the Model S has 85 kWh, of course, not 80 kWh.

Ad van der Meer | May 23, 2012

How will they test the EPA range on the Model S? I assume the regen setting would influence the outcome...

Brian H | May 23, 2012

The % reduction (~15-20) affects ICE cars' ratings the same way. I saw a few before-and-afters for gas models, and some were even more severely impacted.

Note that the 5-cycle does not use steady 80mph highway, but variable speeds up to that number, which means a lot of accel-decel, which is probably even more taxing.

"Volker.Berlin | May 23, 2012
...
When going full throttle end-to-end, the 80kWh battery will be empty after less than 100 miles, "

Where did you get that number? This graph shows 200 miles at 80 mph.

Brian H | May 23, 2012

Oops, the image didn't transfer. Try again:

Volker.Berlin | May 23, 2012

When going full throttle end-to-end, the 85 kWh battery will be empty after less than 100 miles (myself)

Where did you get that number? This graph shows 200 miles at 80 mph. (Brian H)

The number is made up, it was discussed in another thread. Top speed is 125 mph for the non-performance 85 kWh model (see Options & Pricing), now try to extrapolate the above graph. Given the square of aero drag and the fact that the motor is revving close to its upper limit, I think it is safe to assume that the range curve drops even faster towards the end (top speed). The ballpark figure of 100 miles may be too high, I don't think that it is too low.

N.B. This only applies if you go full throttle from full to empty. Don't try this at home.

Brian H | May 23, 2012

Yeah, full throttle would probably do that. I guess that would maybe be SOP on the Autobahn.

I think people had better consider that sustained high speed and/or long-distance driving is going to be best done in an ICE car until the 500/1000-mi battery is available.

And even then, draining it in one high-speed long trip is probably not something you'd want to do very often. That would not only be taxing on driver and car, but would require a really major recharge operation (with the usual time/current trade-off)!

Sub-highway inductive charging would be the only convenient resolution of that dilemma, though I consider that to be mostly pie-in-the-sky, considering costs, logistics, and a host of truly Satanic details that would have their way.

Brian H | May 23, 2012

Just considering the Autobahn, probably the best solution would be to get behind someone doing a speed you like and "draft". Even better if it's a truck!

In my youth I got some amazing speeds and mileage out of a smallish motorcycle courtesy of highway rigs. Had to watch the engine temps, though; cutting the airflow had a price!

Volker.Berlin | May 23, 2012

And even then, draining it in one high-speed long trip is probably not something you'd want to do very often. (Brian H)

I don't even want to do it once. Carefully considering the context of my statement reveals that I was merely illustrating how broad the range of ranges can be, concluding that there is no such thing as "the range" for a given BEV, and that the 5-cycle EPA test may be closer to reality for a greater number of users than the 2-cycle EPA test, even though both these tests are technically "correct" (in the sense of reproducible results).

Brian H | May 23, 2012

Beta testers on the S were claiming to do better than the 2-cycle number, in personal mixed use. I suspect the 5-cycle is more likely a worst-case "torture test" kind of number. I.e., a user should expect to get at least the 5-cycle number, and more likely something close to the 2-cycle. At least with Tesla products. For other makers, maybe not so much! "Under-promise, over-deliver" is not exactly the norm.

Volker.Berlin | May 23, 2012

Brian H, for once, I agree with you.

BruceR | May 23, 2012

Brian H - Please don't draft trucks! We don't want to lose our spell checker. Ever see what happens to a windshield when a retread tire decides to disassemble itself at highway speeds? Take a look as you drive along any interstate for the tire carcasses alongside the road if you think this is a rare event......

There are lots of things we can do as drivers to improve our "fuel" economy, but some of them just ain't worth the risk.

Teoatawki | May 23, 2012

The EPA has taken a lot of heat over the years for reporting mileage estimates which were unattainable in the real world. Perhaps they're trying to do better. Although including 80 mph seems a little over the top.

jerry3 | May 23, 2012

Even if you are a few seconds behind the truck, assuming no strong side winds, there is still a considerable reduction in wind resistance. One of the Prius group members mounted an anemometer on his Prius and took readings.

Brian H | May 23, 2012

On a motorbike, you can feel the borders of the "wake"; there are actually pockets well back, where turbulence is pushing you forward, or of almost "dead air" pacing the truck.

Rod and Barbara | May 24, 2012

GeorgeA, I put together a Tesla Trip Planning spreadsheet using data from Tesla blogs, my Roadster experience and several contributors on the Tesla discussion forum. The spreadsheet can be downloaded from: http://www.box.com/shared/deb4ec8cc468632eb9b7.

For a 240 trip in a Model S 85 kWh vehicle on level terrain with climate control on you can drive 65 MPH and arrive with 10% battery charge remaining. At 70 MPH you would arrive with 2% battery charge remaining. I couldn’t find a definitive source for climate control degradation so the spreadsheet assumes a 5% degradation. If you want to be very conservative and allow 10% degradation, then you arrive with 5% battery charge remaining at 65 MPH and you cannot drive 240 miles at 70 MPH without recharging enroute.

Brian H | May 24, 2012

R&B;
In the latter situation, you'd probably adapt by "pulsing" the climate control periodically to bring it back to comfort level. You could probably cut the drain in half doing that.

GeorgeA | May 24, 2012

A future option will be a 500 mile battery pack. (stephen.kamichi)
What we really want, of course, is 500 miles by the EPA 5-cycle test! :-) (Volker.Berlin)

The engineers are working on it I’m sure. My road range fear will disappear once Telsa announces this futuristic 500 mile battery pack!

If you think ahead driving in city you rarely need to do that so it's actually something that makes real world results better than EPA test shows. (Timo)

True. Isn’t EPA testing going to rate just highway driving range and then have a separate in city rating? Most people want to know what to expect when taking a highway trip and what to expect when driving around town not just the combination of the two. I will be thrilled the first time I am able to drive even 240 miles on a single charge, 300+ miles would be incredible. Besides the Roadster, nothing comes close to this.

GeorgeA, I put together a Tesla Trip Planning spreadsheet using data from Tesla blogs, my Roadster experience and several contributors on the Tesla discussion forum. The spreadsheet can be downloaded from: http://www.box.com/shared/deb4ec8cc468632eb9b7. (Rod and Barbara )

Thanks for the detailed spreadsheet on trip planning. It will be useful. There are of course numerous variables to factor in when determining range and even charge times when planning a trip. ie. Driving alone vs a full carload of people with luggage (overall weight) , using AC, headlights, music, internet, tire pressure, traveling speed, driving against any head wind, terrain such as mountains etc. Perhaps someone on these forums will collect and track some real life range data and recharge time rates we could supply once all of us have received our S Model.

EdG | May 25, 2012

@Brian H you'd probably adapt by "pulsing" the climate control periodically to bring it back to comfort level. You could probably cut the drain in half doing that.

If you're turning the climate control on and off every few minutes, you might as well leave it on. Otherwise every time you turn it on the car has to spend more energy per minute just to get you back to room temperature. There are some savings, but I think you'd be hard pressed to verify such small numbers in an experiment. Just leave the climate control on or off.

David70 | May 25, 2012

Yep, you're probably better off setting it at a temperature slightly closer to outside temperature than turning it off and on.

zero2hide | May 25, 2012

Living out here in CO, I was wondering if any of the "super-minds" on this forum have any projections on the battery drain while driving from Denver to Aspen for example? About 3,000 ft difference.

We have a turbo charged VW Tiguan that helps on some of those steep long draws to the mountains, but my ole BMW Z3 gets winded easily :)

Rod and Barbara | May 25, 2012

The spreadsheet mentioned in my May 24th post above predicts a fully charged 85 kWh Model S will make the 200 mile trip at 55 MPH and arrive with 30% battery charge remaining, a penalty of 6% battery charge over the same trip on level terrain. There is a wide range of estimates for Wh required to ascend 1,000 feet. In my research on the forum I found numbers for the Roadster from 1,000 Wh to 1,465 Wh. My spreadsheet uses 1,214 Wh/1,000 feet of elevation gain for the Roadster (average of the 5 data sources I found on the forum) and 1,706 Wh/1,000 feet of elevation gain in the Model S (increased by the ratio of Model S to Roadster weights).

zero2hide | May 25, 2012

Thanks Rod & Barbara!
Did not see the trip planning sheet link.

jerry3 | May 25, 2012

- If you're turning the climate control on and off every few minutes, you might as well leave it on.

In the Prius I've found the best results happen when. In the Tesla by pre-cooling the car while it's still charging you should be able to reduce the range impact by a considerable amount:

1. Whenever there are five bars or less, drive for regeneration rather
than gliding. You want to keep the battery up without running the
engine, otherwise the engine will run faster and sooner.

2. Avoid acceleration that uses the battery.

3. Don't set the temperature below 73. (I run 74, some folks run 76)
I've tried various temperatures, and below 73 actually makes me feel
hotter.

4. If you are stopped in really bad traffic, nothing is going to help
your mpg, but it will still be better than a conventional car.

5. Use auto. The Prius' a/c is one of the most radical (and nifty)
things about the car. It uses an electric variable speed scroll
compressor, so it doesn't always run full tilt. There are five sensors
(solar, humidity, vent, temperature--foot, temperature--filter) and a
dedicated ECU to keep you comfortable with a minimum expenediture of
energy.

6. When starting: if the car is hot first open the windows to remove
the superheated air. Then adjust the temperature upwards so that the
recirc light goes out (or at the second-to-highest (85F) setting if the
recirc light doesn't go out--the highest setting forces heat).

7. As soon as the recirc light goes out (if it was on) or after a
couple of minutes driving (if it wasn't on) , reduce the temperature
by two clicks. The recirc light should stay off.

8. Repeat #7 until the temperature is comfortable.

9. Try to keep the battery icon at five or six bars. If it goes lower
the engine will start when it wants to rather than when you want it
to. So drive for regeneration until it reaches six bars, then pulse
and glide until it's back down to five, then repeat.

9a. If you have a Scangauge. Drive at IGN 14. This will keep the
battery up for long periods of time resulting in better overall mpg.

What you'll notice:

A. The comfortable temperature will be higher than what you expected.

B. The SOC won't drop like a stone--even during stop light waiting
periods.

C. There won't be a blast of air when the system starts.

D. MPG will improve a lot because the a/c hit is reduced to 3-4 mpg (out of 60-70).

Timo | May 25, 2012

@zero2hide

Height difference causes smaller battery drain than intuition usually says. It's all mass and elevation: U=mgh. If we assume Model S weight to be around 4000lbs (still no actual info about that) then 3000 feet climb (assuming 1 feet is about 30cm) is:

1814kg*9.81m/s^2*900m = 16015806 joules ~= 4.5kWh

(roughly, gravity isn't same everywhere and we don't know the actual weight of the car).

Going in opposite direction you gain that potential energy back so the net result is very close to flat road as long as you don't need to use brakes (regen isn't perfect either, best result would be gliding without needing to use motor in either direction, but that rarely happens).

stephen.kamichik | May 26, 2012

According to TM rep.....the model S weighs 4400 pounds.

Timo | May 26, 2012

I'll wait for actual specs for that. Tesla rep info isn't the most reliable source, more like guesswork and inside rumors.

Roblab | May 26, 2012

Actual experience driving a 4000 lb EV in mountains:

It takes roughly ten miles of energy to go up 1000 feet. For a 3000 foot elevation in ten miles of road, it takes roughly 40 miles of energy.

You DO NOT get it back from regen. 1000 foot drop gives you back about one third of what you spent on the climb. If you go up 1000 feet, down 500 feet, repeat to 3000 feet, you will spend 50 miles going up and get back 12 miles of regen. PLUS the actual miles.

Slowing down is your best bet for longer range. Massive savings from slowing 20 mph. Take surface where you can. Learn to accelerate slowly, smoothly. SHUN high speeds, even behind trucks. Wear appropriate clothing, light in warm weather, heavier in cold, so you can use less AC/heat pump. Use vent fan. Let windows pull air through, as Drag losses are reduced considerably at lower speed.

Timo | May 27, 2012

To clear misunderstandings, I said "net result is very close to flat road". Flat road. I didn't say it is free energy, you still have exactly same losses involved as in flat road. But you do get all that energy back in one form or another (potential energy is potential energy, energy cannot disappear, it can only be lost in inefficiencies like air drag).

@Roblab, which EV is that?

jerry3 | May 27, 2012

Roblab, Your experience matches mine albeit mine is in the Prius and not in an EV. Regen captures about 1/3 of the kinetic energy (in the absolute best case it might capture 50% but I think you'd have to have just the right grade for it to do so--not so steep that the speed increases and the energy gets eaten up by aerodynamic drag).

Roblab | May 27, 2012

@Timo

RAV4EV.

There are also losses in changing energy from one type to another, so regen is not near flat road. Just saying.

I am sure that one of the things I will do first thing is watch how much energy I give and receive driving my 1000' hill. You lose 10 miles up and get 3 miles back on a 6 mile drive. 16 miles of energy up, 3 miles of energy down. 19 miles energy used in 12 miles of flat road on the map.

Timo | May 27, 2012

Well, I didn't say you gain that energy back by regen. I just mentioned it saying that it isn't perfect either.

Best way to get it all back would be allow car to just glide down collecting all the speed it can get (though there is a speed where you start to lose more to air drag than you would with regen keeping it at speed limit). If downhill isn't steep enough to keep you at speed limit and you need to accelerate it then matches pretty closely flat road. Regen gives you only that part which isn't lost in other inefficiencies minus regen losses (which should be a ballpark of 30% in Tesla cars gaining you 70% of power needed to decelerate).

When we talk about regen it isn't actually energy but power:

Downhill requiring 5kW worth of deceleration at 60mph: 20kW lost to air drag and rolling, 5kW * 70% goes to battery = 3.5kW. That's not a big portion of the losses: 3.5kW of 25kW is only 14% of the power it is losing even with 70% efficiency.

Timo | May 28, 2012

10 miles extra when going up to only 1000 feet? That doesn't sound right.

U=mgh = 1800*9.81*300 = 5297400 joules = 1.47kWh. That's 147Wh/mile if that is ten mile worth. Model S makes 300 miles with 85kWh which is 283Wh/mile RAV4 probably uses closer to 400Wh for one mile. This means that you should have lost only three to four miles of extra energy, not ten. Something is very badly off here. What kind of speeds are we talking about? Not a straight line requiring accelerations and decelerations? Bad road surface? Can you post actual energy usage here with comparable results from flat surface? I'm curious because this might be the case where reality doesn't match with theories and I would like to know why. Maybe worth of its own topic.

ddruz | May 28, 2012

Timo, For what it is worth I lose approximately 12-16 miles going up and down four 1000 ft mountains at an ave speed of 50-55 mph in a particular round trip commute in my Leaf. That is in line with your calculations.

Thumper | May 28, 2012

ddruz can you clarify that mileage loss due to climbing? Is the 12-16 mile loss cumulative for 4 climbs or per climb. Is each climb 1000ft of total gain or over a 1000 ft pass with a lower actual climb? Thanks

Volker.Berlin | May 28, 2012

Roblab, great data and explanation. That's really relevant experience. Thanks for sharing!

ddruz | May 28, 2012

Thumper, To answer your question: the 12-16 mile loss is cumulative for four climbs from ~50 feet to ~1050 feet and back again to ~50 feet.

Timo | May 28, 2012

This is OT, but interesting. I start new topic for this.

Timo | May 28, 2012

Made new topic in general "Effect of road conditions on range" for this.

Roblab | May 29, 2012

@Timo

Hey, my friend. I have always had the experience with the learned intelligent scientific people that it can't be this way. Trouble is, that's the way I measured it, in 6 years 60,000 miles. Most every one I talk to agrees that you get only about 1/3 back on regen, and it takes 10 miles of energy to go up 1000 feet. Rough ball park, easy to remember.

FWIW, I drove my RAV at 45 up my hill. On the flat, for grins, I got 112 Wh/mi. Most got around 250 Wh/mi in everyday driving. That's about right: 25kWh gave about 100 miles.

I hope the Model S does better, but a lot of it depends on speed and acceleration. At 45 or less there isn't a lot of drag loss. Passing the other drivers in the passing lane halfway up the hill would eat it up.

It will be interesting to see real world experience for the S. HOPEfully we can get some data in less than a month!