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Model X range with 85 kW

Model X range with 85 kW

I am wondering what kind of range will the Model X get. At highway speeds, since fuel efficiency is largely dependent on drag, the Model X, with its higher drag coefficient should travel shorter distances with the same battery charge that the S.

Because of that, I was expecting Tesla to offer slightly bigger batteries option for the Model X compared to the S like 70kW and 95kW for example.

Has anyone seen anything about the expected range of the X compared to the S?

NumberOne | January 24, 2014

The Model X is also very well designed, and while not as efficient as the MS, I do not expect the difference to be more than a single digit percentage figure. In other words, even with the 60kWh equipped model X one should still be able to travel from one super charger to the next.

Koz | January 25, 2014

It doesn't make sense to make slightly different battery packs for the X but it makes a lot of sense to engineer a larger pack to add a third size. I would be very surprised if they don't add a 100-110kwh pack and offer it in both the X and S. The only way they would change the existing pack capacities that makes sense is if they do it for the S too so there are only 3 pack sizes in total.

Also expect a new cell chemistry for the battery packs at that time. The 100-110kwh pack should weigh close to what today's 85kwh pack weighs. If they stick with these three size and achieve the expected gravimetric energy density improvements, then EPA highway ranges (hopefully the EPA will come to its senses by then and provide rated ranges for both city nd highway) will be about 175, 225, and 270. Perhaps Tesla only offers the two larger sizes in the X, but I hope not.

Remnant | January 26, 2014

While it is reasonable to expect a 100 kwh battery pack upgrade, weight reduction could also improve the range.

In this day and age, wouldn't it also be reasonable to hope to replace heavy mechanical gears with electronics?

The weight thus eliminated could go into an upgraded battery pack, even before the battery chemistry improvements could support higher energy densities and smaller battery sizes.

This would require full-time AWD, with four motors rather than two.

Brian H | January 27, 2014

There's only one gear, a tiny weight wrt the whole car. How are you going to link slow wheels and fast motor without it?

NumberOne | January 27, 2014

What Remnant is suggesting would actually not decrease the weight. Each of the motors weigh roughly 150 lbs. Even if the motors were smaller, the weight of the car will increase rather than decrease. The front motor is going to be smaller than the one in the rear already.

One would do well to remember that these are very powerful motors. The standard rear motor produces more than 300 lb-ft of Torque, and for the performance version it is even higher.

dortor | January 28, 2014

I'll go out on a limb here - but the car will be heavier and have more drag - both are not going to help range

EPA Rated Range for a Model X 85 kwh = 245 miles
EPA Rated Range for a Model X 60 kwh = 190 miles

anything better than this and I will be pleasantly surprised.

jeffaa | January 28, 2014

I'm thinking they'll have a bigger battery for the X than what they offer now. Going out on a limb myself here: the 60kwh battery won't be an option on the X. But the 85 will be, along with the next size up.

jjs | January 28, 2014

Do we know that the X will have a larger coefficient of drag? I believe the only thing we know for sure is that it's cross sectional area will be larger which is a component in determining the drag force.

If the X's coefficient of drag is lower than the S it is possible that the overall drag force is lower than the S. Not likely, but possible.

dortor | January 28, 2014

the mirrors might make a difference - I've heard the side mirrors are some disproportionally large amount of drag - if they manage to get rid of them (blocked by regulations at this point in time) then they could drop a very expensive aerodynamic element of the design…

we don't know what it's drag is or it's weight or it's price or it's range...it's possible for it to be a lot of things, but it's unlikely to have less/equal drag to a model S, and it's unlikely to have equal/less weight (although battery tech may lead to an 85 kWh Model x batter being less heavy than a 85 kwh Model S battery, but then they could do the same for the Model S - this could in theory allow them to keep same "range" as the original model S, and upgrade a new Model S to more range…

it's all a mystery at this point in time - but I"m sure Tesla has a plan.

I believe it's highly unlikely for the Model X to be more efficient than a Model S given some inherent design requirements of an SUV…but again I'm open to being surprised.

Brian H | January 28, 2014

dortor;
Your first 4 " it's " are wrong, and the next 5 are right.
his, hers, its
he's, she's, it's

Now you'll never look illiterate and confused again!

Your range estimates look about right. I wonder if the MX will lose much traction with the wings extended. ;p

dortor | January 28, 2014

yeah - I noticed that when I posted - but the forums don't let you edit your post

I not do have no real trouble with grammar most of da time I ain't never had it being wrong.

ian t.wa.us | January 28, 2014

While I'm not counting on it, I'm hoping for a larger battery in the X as well.

The drag will be higher in the X for sure. Larger frontal area = higher drag. I believe anyway.

jjs | January 28, 2014

@goneskiian

Drag is a product of the coefficient of drag and cross-sectional area (and velocity and viscosity of the medium being traversed).

So without doubt the cross-sectional area will be larger. The question is what is the coefficient of drag. That will be the most telling factor in whether the overall drag is greater than the S.

Probably will be larger but as of yet we just don't know.

ian t.wa.us | January 28, 2014

I should be careful as I know there are likely some aerodynamisists that post here. That's probably you isn't it jjs? ;-)

Thanks for pointing that out. I'll not speculate any longer.

Cheers!

Remnant | January 29, 2014

@ LeonardD | January 27, 2014 (ten entries back)

<< What Remnant is suggesting would actually not decrease the weight. Each of the motors weigh roughly 150 lbs. Even if the motors were smaller, the weight of the car will increase rather than decrease. >>

Here is what Tesla says at http://www.teslamotors.com/roadster/technology/motor:

"... the Roadster [as well as Model S] has only a single speed gear reduction; one gear ratio from zero to top speed. Switch two of the phases (this can be done electronically), and the motor runs in reverse. No need for a reverse gear. Not only is this design incredibly simple, reliable, compact, and lightweight, but it allows a unique and exhilarating driving experience. The Roadster accelerates faster than most sports cars and whether driving on windy mountain roads or cruising down the highway, there’s always instant torque."

I guess the torque is cumulative. If you divide the single motor torque into 4, you get smaller motors, maybe 40-50 lbs, but you can dispense with the mechanical differentials, which are heavy.

Bubba2000 | January 30, 2014

Tesla will most likely keep the skateboard, drive train as close as possible to MS. It will reduce R&D, manufacturing and aid in economies of scale. I would like to see them keep the design simple... even the Falcon doors make no sense. Regular doors are cheaper and less things to break down. Even AWD will take time.

It is simpler to just increase the battery capacity by adding extra cells. I read that the pack can pack 8,000 cells, but only has 7,000 for the 85 KW-hr. I would think that they could pack 100 KW-hr if the design allows for that. Charge an extra $10,000.

Remnant | January 31, 2014

@ dortor | January 28, 2014

<< I've heard the side mirrors are some disproportionally large amount of drag - if they manage to get rid of them (blocked by regulations at this point in time) then they could drop a very expensive aerodynamic element of the design… >>

If you revisit the MX page, you should notice the side mirrors have already been replaced with tiny periscopes at the end of short stems.

This arrangement might hide a problem, since a stem might not resist a direct blow or yank across it and could even be perceived as an opportunity for vandalism or theft.

In my opinion, these side periscopes should be enclosed in unbreakable and ungraspable, small, smooth, flat humps of protective metal or hard plastic, transparent around the viewing end, but not allowing access to the cameras from outside the car.

Tom A | February 4, 2014

*sigh*

The Model X is going to have the same battery pack options for this current generation platform as the Model S: 60 and 85, same size, etc. (swappable).

The Model X is going to have a larger drag coefficient than the Model S. It has a larger cross-section, and it is higher off the ground. Both issues contribute significantly to drag.

However, the Model S has the lowest drag coefficient of any production vehicle ever sold in the US (.225 or .24, I've seen both listed at different times). Due to range concerns and sharing a general shape and styling, I would expect the Model X to have the lowest, or one of the lowest, drag coefficients for any production SUV/minivan/etc. ever sold in the US.

David Trushin | February 4, 2014

Brian H. Letterman mentioned a survey on his show one night. The question was "Who would you like to beat up the most?" 92% of respondents said "people who correct your grammar". The other 8% said "Don't you mean to say 'whom would you like to beat up the most'? How does it feel to be part of the 8%?

Seriously, keep it up. My particular pet peeve is when people misuse the pronouns; I, me, him, he, she, her. As in "This car is just the thing for she and I". Or even worse, "... for her and I".

pierre.roberge | February 4, 2014

I think it would be easy for Tesla to add a 1000 cells like @ Bubba2000 suggested. They have a modular battery pack design where they put cells into modules that are physically independent from one another to prevent, among other things, spreading of heat/fire. They could just add a few of those modules and voilà. I am sure there is some space in there left.

Also i assume the battery pack software has been designed to use any number of modules that are present so, for example, when a module fails, the car still works albeit with a lesser range. Adding modules or having less modules because of failure will be adjusted in software automatically. This is just good design.

So.....bumping the battery pack would not require any re-engineering whatsoever, me thinks!

My bet is on a slight pack capacity increase.

pierre.roberge | February 5, 2014

Another thing I heard is that since electric motors consume less current at lower rotational speed, it would make sense for the Model X, since it will have 2 motors, to optimize one for city driving and the other for highway driving.

Both could work together for hard acceleration but for cruising, one will be enough.

And contrary to ICE 4WD cars, you could have a few millisecond response time to engage the second motor if you needed to.

Doing all that would lower the Model X energy needs.

Brian H | February 6, 2014

Yes, I think JB confirmed that in the Oslo talk.

bent | February 6, 2014

What will the driving experience be like if your car semi-randomly switches between being a FWD and a RWD?

NumberOne | February 6, 2014

There should be no noticeable difference. One thing that gives a front wheel drive vehicle a different feel is the steering. With the model X you are probably not going to notice much difference. With my F150 FX4, which switches manually (on the fly) there is a clear difference in the steering with 4x4 engaged. It is however, only noticeable at a low speed sharp turn. I suspect that the mechanics of the Tesla drive train will improve this issue.

Also, from what I have heard Elon and JB say, the Model X AWD system is truly intelligent, and that the car will be mainly RWD, and not completely switch to FWD. They are probably still working on efficiency though.

Iowa92x | February 11, 2014

Elon says 10% efficiency hit on the X vs. the S, mostly due to higher coefficient of drag. Tesla will compensate with a higher output battery for the X.

dortor | February 13, 2014

@Iowa source on this information?

Iowa92x | February 13, 2014

Dortor, here's a link to Elon in Oslo speaking on the X, with a quick text summary about X drag coefficient. Brace yourself for ignorant questions from owners in the audience like the gentleman asking why there is no iDrive-like joystick to control the screens. http://www.greencarreports.com/news/1090225_elon-musk-talks-tesla-model-...

dortor | February 13, 2014

thanks Iowa - this helps a lot…

Solarwind | February 18, 2014

I am a little worried about the X's range as our current electric car takes a hard hit in cold weather, up to 50%. Looks like in my area it could be 250 miles between stations. Sure don't want to keep a spare car.

Remnant | February 19, 2014

This is a good point and would suggest a battery heater/cooler -- with its thermostat setting at the optimum of that battery -- might be beneficial.

Expect insights regarding this matter from the MS owners in the North-Mid-Atlantic states, given their exposure to frigid temperatures for the last several weeks.

ian t.wa.us | February 19, 2014

Maybe I don't understand your statement completely, but you do know the pack is already actively heated and cooled don't you?

vandacca | February 19, 2014

@Remnant | JANUARY 31, 2014

>> If you revisit the MX page, you should notice the side mirrors have already been replaced
>> with tiny periscopes at the end of short stems.

It appears that the MX will have regular mirrors due to regulations in most countries. If you wonder what that would look like, check this out:

http://instagram.com/p/i11-LDhMTL/
http://insideevs.com/tesla-model-x-spotted-on-public-road-in-culver-city...

--Dan

Remnant | February 19, 2014

@ goneskiian | February 19, 2014

<< ... you do know the pack is already actively heated and cooled don't you? >>

No, I didn't. Thank you for sharing this with me.