Tesla Updates Range Of Model S Family, 85 kWh Cars From 253 (P85D) to 270 miles (85D)*

DEC 30 2014 BY JAY COLE 22

Ever since the P85D initially hit the market and received a lower than expected EPA rating of 242 miles of range, there has been quite a bit of speculation on the ‘how and why’ behind the number, as well as what to expect with the other newly introduced “D” model – the standard 85D.

It turns out that a recently tweeted “sleep mode” for the dual motor cars will improve the P85D range to 253 miles, and will allow the 85D to achieve 270 miles of range – which is better than the 265 the current/original variants of the Model S (85, P85, P85+) are measured at.   The software update is expected by the end of January.

Tesla Model S Family Ranges Updated

Tesla Model S Family Ranges Updated

Tesla’s Chief Technical Officer, JB Straubel explains:

“As the Model S family has expanded over time it has become more relevant to compare range from one variant to another with a consistent set of assumptions so our customers can know what to expect and make the best decision to fit their needs. This can be a bit difficult since the background test methodology and standards from the US EPA are evolving over time. There are also many customer vehicle configuration choices, both before and after purchase, that can affect range as much as or more than the vehicle platform choice itself. The most important example of this secondary configuration is the wheel and tire selection. This short paper will hopefully help to compare amongst all of the Model S family and understand how tire choices impact range as well.”

Tesla also noted the “cruising” ranges on the Model S, something the company has used to promote the “D” family of cars previous to the official EPA ratings, as the AWD format allows for greater miles to be driven at speed.

Tesla Model S Family "Cruising" Ranges

Tesla Model S Family “Cruising” Ranges

Mr Straubel also gives consumers a primer aerodynamics, the effect tires and wheels have on range, as well as speed.

Check out the full report (and fancy graphs) from Tesla’s CTO below:

The physics of aerodynamics affects all moving vehicles (gasoline or electric) the same: reducing efficiency and range at higher speeds. This effect is more pronounced at higher speeds since the drag force of the wind on the vehicle increases with the square of the velocity, from 35 to 70 mph it doesn’t just double but goes up by four times!

Despite this aerodynamic challenge, highway cruising is where the unique benefit of the dual motor cars, to torque sleep one of the drive units when not in use, is most apparent. Much like a modern computer that can actually sleep in between keystrokes, the dual motor Model S will quickly torque sleep a drive unit when torque is not needed and instantly wake it up as the accelerator is pressed to command more torque. It continues spinning while asleep and the digital torque wake up is so fast that the driver can’t perceive it. It is far superior to the slow and awkward engine start-up on stop-start hybrid vehicles.

The software update to implement torque sleep will be downloaded to the dual motor fleet by the end of January 2015 and will substantially improve the range of dual motor vehicles by roughly 10%. All tables and graphs in this paper are shown including the benefits of torque sleep.

Performance Tires and Wheels
With tires and wheels there are some physics trade-offs between handling, traction and efficiency (rolling resistance and aerodynamic drag.) At the most intuitive level, as a tire becomes more sticky it will corner and accelerate better but also have modestly higher rolling resistance. Customers can make decisions on tires and wheels independently across all variants of the Model S. Of course these decisions are also often changed throughout the life of the car (summer vs. winter tires for example.)

The 19″ Cyclone wheel and tire that we offer on most of our vehicles is the best configuration for range, efficiency and cost effectiveness. The 21″ wheel/tire upgrade yields substantially improved handling performance and vehicle dynamics. The 21″ performance tires are a more commonly selected option on our performance variants (P85, P85D and formerly P85+) since many of these performance-oriented customers want the best possible handling. There is however roughly a 3% reduction in EPA 5-cycle range (compared to the values presented in the table above) for the selection of 21″ performance tires to any of the Model S variants. For customers who care about handling and performance driving this is a trade-off that we think is well worth it. For customers who are focused on range, efficiency and best value the 19″ wheels can be configured onto any Model S variant to achieve the values in the EPA table above.

As an example calculation, if a standard Model S 85 with 19″ tires having 265 miles of range is changed to 21″ tires the range would be reduced by ~3% to about 257 miles. This is the range that most customers of the former P85+ configuration experience since nearly all of those variants are configured with 21″ tires.

It is also worth noting that all new tires have a break in period for the first ~1,000 miles where the total vehicle efficiency is reduced by up to 5%. This can surprise (negatively) new owners or customers who have just changed their tires but will quickly improve back to a normal baseline.

Range vs. Speed
There is naturally a strong sensitivity to range based on vehicle speed as mentioned above and we have discussed in some detail in the previous Model S range and efficiency blog.

The best way to see a more complete picture of this is actually in a graph of what range is possible versus driving speed.

Figure 1

Figure 1

And if we look in even more detail at the differences just between the 85kWh battery pack variants you can see the interesting complexity in how the dual motor operates. At some speeds the P85D is more efficient than the base 85 and equivalent to the 85D. At other, higher speeds the 85D and 85 are slightly more efficient, with higher range, than the P85D.

Figure 2

Figure 2

Summary
Which battery, drivetrain and tire configuration is best for you will depend on what kind of driving you enjoy most. At Tesla we pride ourselves on transparency and providing customers clear data to understand our products. With the information above hopefully the choices and performance expectations are clear.

We have also added all of this information, and even more such as cabin heating and air conditioning loads (HVAC), day/night driving, windows up/down, 19″ or 21″ tires and outside temperature into a powerful range tool that you can use to simulate any driving conditions and any vehicle choices. Feel free to play with this and give us feedback if we can improve it!

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22 Comments on "Tesla Updates Range Of Model S Family, 85 kWh Cars From 253 (P85D) to 270 miles (85D)*"

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George Parrott

What other car choice can one make to go from simply quick and enjoyable (85S) to insanely fast and exciting (P85D) without losing at least 50% in mpg/range?

High performance Audi and BMW vehicles push the edges of the “gas guzzler” penalty box, but the Tesla P85D buries all of them in the daily stoplight show and loses maybe 3-5% in range? Simply amazing IMHO. My P85D arrives early February after 20 months of joy with an S85.

CherylG's_DirtyLittleSecret

+1!

Unless Tesla wants the Model X to have sub-200 mile range, they’ll ditch the 60kWh version. Just 85kWh regular and performance.

Ahldor

Yea, if I was Tesla I would have put the largest amount of cells into the battery to make it >105 kWh or something, together with the release of the Model X, and offer Model X with 85 and +105 kWh. A few months later the larger battery would be available for the Model S aswell.

Elon said last week (in a now-deleted tweet) that battery upgrades for the Model S were far off. As much as I’d like to see a 100-110kWh pack, I’m becoming more skeptical of it.

I think we wont see larger capacity packs until we get to the second generation Model S/X in 2018 or 2019 (after the Model 3 launch). Using cheaper GF packs and some moderately improved chemistry they’ll probably be able to make an 80kWh base pack (250-270 miles) and a 110kWh pack (350-370 miles).

Ahldor

Well, “longer term” in Tesla words doesn’t necessarily mean far off in general car industry term. I think it’s more like 2 years.

If they wait until 2018 or 2019 to release a bigger battery then other car manufacturers like Audi probably will have longer range EV’s for sale, which would be unfortunate for Tesla.

I cannot see a better solution than offering a larger battery for the Model X release. The customers have waited years for Model X. They will pay another $10k or so for a car that has 10% less range than the Model S, plus the X will have towing ability which also increases the need for a larger battery.

No, it would actually be sad news if Tesla keeps their 85 kW as top notch for the Model X. The X needs a bigger battery way more than the Roadster needs it’s upgrade.

Steve Strange

Well I don’t know about Audi — has anyone heard about *any* Audi BEV as of yet? Plug-ins, yes. But no Tesla all-electric competitors. The only vendor that’s even given a hint of significantly longer EV range in the future is Nissan, and that’s probably two years away. Someone needs to start competing with Tesla.

Ahldor

Audi has flagged for atleast two long range BEV’s in 2018-19. WW is another player to coount with since they also have announced interest in BEV’s. Sure, this is what Tesla wanted all along. But it is still no reason for Tesla to not make their best effort into making supreme products. Remember that people’s expectations for a new EV goes up as time passes.

Of course Musk says a bigger battery is not coming soon. Otherwise the demand for the Model S will go down short term until the bigger battery is released. Eveeyone knows that batteries are expected to improve long term anyway.

pjwood

AWD may hasten the 100+kwh battery, given the around town numbers. those are less important than hwy, but the drivetrain can really spill watts.

koz

Try nearly irrelevant for around town numbers for a 200+ mile EV.

pjwood

The average electric consumption of a dwelling, in the U.S., is under 1,000kwh a month. I can see the P85D adding that much, pretty easily. It’ll still be a heck of a lot cheaper than gas, but I’d still call that relevant.

Waiting

I only started watching the number of superchargers coming online in May, 2014. If my count is close to accurate, only 51 Superchargers came online since May 27, 2014. Not sure it that is outstanding news or worrisome because of how many Tesla claimed there would be by the end of 2014. With the number of superchargers online, the 84D has a leg up.

Waiting

Typo: 85D

scottf200

Check out the world wide chart

Gustavo Bittencourt

The site supercharge.info counts exactly 221 new superchagers wordwide and 51 in USA since May 27, 2014.
https://docs.google.com/spreadsheets/d/14HvXk49ohZ-vHR_FZWgOJBrzcU4uyDDCh-LGtguSyis/edit?usp=sharing

ffbj

Yeah really. It’s like after an area is saturated, or at least the skeleton is built, you move on. You can always flesh it out later. I think it’s one of the great achievements of Tesla. Chill.

Anon

“Torque Sleep” is cool. 🙂 Nice info, nice graphics. Great clarification on the dual motor range topic. Thanks Tesla!

Phr3d

makes me wonder about future tech – high-speed obviously faces wind-aero, but otherwise a lower load, so the small(er) front motor does all work at different (much higher) gearing when cruising at high speed? Hard to make leap from ICE (I sorta’ know what works) to EV here, as it -seems- like that addresses some EV issues, but I’ve no idea what Other issues may arise when you O/D a motor vs ICE.
As I’ve said before, better minds than I have already (apparently) discarded gearing/transmissions, but what about a different/secondary motor?

Bill Howland

Color me very confused. Ok so they shut off the juice to the front motor occassionally… Its still spinning fast (typical Tesla Screamer) so you still have gearing losses and windage losses. Since the rear motor is powering the car and the 2wd unit doesn’t have the front losses, it still doesn’t make sense to me, regardless of the cute “torque sleep mode” name.

Why an 85 should get lousier mileage than an 85D is still a mystery to me.

I thought someone (PJWOOD?) said they couldn’t match tesla’s results??

scottf200

P85D – rear as front is more efficient
85D – front or rear (same size) optimized for best efficiency

pjwood

Bill, I think a smaller rear motor on the 85D, than the S85, is where Tesla is making its “270” EPA AER claim, as higher then the S85’s known “265”. It’s a small difference, but if they can “idle” one of the equal sized motors of the 85D, theory holds that these numbers are correct.

In practice, P85D TMC posters are getting what looks like 220-230 miles, at 65mph. This is far short of “285 miles” Tesla first started claiming at the launch event, and on the web. The question being whether ‘normal’ mode adds them back.

Personally, I only did one (70 degree) range drive that achieved 280 miles, with ~2 remaining. Speeds were mixed, but far lower than a 65mph average. With deliberately limited accelerations, it really isn’t a good proxy. I appreciate Tesla’s point, about strict highway. As Jerome says in his blog, wind resistance is at the square of velocity. Go 55mph, if you really, really have to, and you’ll be shooting for 300 miles in good weather. Slowing down is the same bail-out it is for gas. You’ll get still “get there”.

Priusmaniac
The graphs above are very interesting but they stop short of the entire speed range the Model S is capable off, so I wonder what goes on at higher speeds like the one you do on the autobahn. Perhaps not the extreme of 130 mph but it would be at least interesting to know what goes on at 100 mph which is a quiet typical speed there. Since at 100 mph distances are quickly driven it is therefore all the more important to have that information. Having it could allow a new application in the car that according to your destination and the charge remaining in your car could instantly calculate the maximum speed at which you can drive the distance and still make it. A kind of speed optimization instead of energy optimization. For a programmer this should be quiet feasible to integrate that in a next software update. It would be handy to know you can drive faster but also that you can make it, to a destination, at a lower calculated speed. Actually further on, it can be even better if you integrate the road speed limits information because only the autobahn is free speed not the… Read more »