Is there a difference in the electric engine itself in the 3 standard models? (40kW,60kW,85kW)?

Is there a difference in the electric engine itself in the 3 standard models? (40kW,60kW,85kW)?

Is there a difference in the electric engine itself in the 3 standard models? (40kW,60kW,85kW)? Is the performance difference solely due to the max amperage the engine can draw?

If Tesla were to offer improved batteries in the future (or just allow replacement with larger batteries), will the 40kW version be able to perform the same as the 85kW?

Also, what makes the performance model different? Is there a completely different engine in there, or is it just "tuned" differently?

s_curve | 14 novembre 2012

The main difference between the 40, 60, and 85kW batteries is range. The 60 and 85's will also be configured to leverage the forthcoming supercharging stations. With regard to the Performance version of the 85, it is equipped with a high performance drive inverter that delivers a marked increase in both torque and bHP. I personally chose the P85 because I thought it was more 'futureproof'. There is value in the 40 however in that for considerably less cost than the 85, you still get pretty solid performance from a sedan with a curb weight of more than 4700 lbs.

Vawlkus | 14 novembre 2012

The motor itself does not change, unless you get into the Performance model.

DTsea | 14 novembre 2012

Yes the Performance and Signature Performance have a higher power inverter and motor.

Brian H | 14 novembre 2012

Are the Perf motors themselves different, or just the inverters?

ModelS3P | 14 novembre 2012

I asked this exact same question in an e-mail to Tesla a while back. The motors are all the same. If you start with a 40 kWh pack, then in the future upgrade to a bigger pack, you will get the increase in performance (0-60 time); however, you will no be able to gain supercharger access since that requires additional hardware to bypass the chargers (plus you need other beefed up wiring to handle 90-100 kW).

As for the performance model, it was my understanding that the motor was the same but the inverter was different.

ModelS3P | 14 novembre 2012

no = not

HenryT2 | 14 novembre 2012

Thanks for the info guys. It's made me a little more comfortable about ordering the 40kW model. Sounds like, if batteries become cheaper/more efficient, it'll be worthwhile to upgrade. For now, I only do more than 60 miles in a day a few times a year. Then I'll use my SUV. Even with the best supercharger network, you can't beat the convenience of an ICE, for now.

If I should ever decide I need the network, looks like I'll have to sell the 40kW. I'd certainly prefer to futureproof my car, but since I have no idea what the network will look like in my neck of the woods (Washington state), I'd rather not spend $10/20K more to get something I don't need on the off chance that I might need it in the future.

s_curve | 16 novembre 2012

That makes perfect sense HT2. Each buyer has to assess based own their own driving profile and needs.

Brian H | 16 novembre 2012

Elon says handling used Roadsters, MSes, and MXes might end up as a major profit center/business for tm. Sounds like "flipping" the 40 in a few years might be easy.

sergiyz | 17 novembre 2012

There's a bit of conflicting info on the motor itself.
I've heard it both ways, i.e. that the motor in Perf is the same with only the inverter supplying higher current, but another rep told me the motor itself has extra windings too.
Replacing the battery pack with a larger version might not be a trivial task.
I don't think Tesla themselves know yet how they account for a difference in weight and weight distribution of a 40kw pack vs 60kw pack vs 85kw pack.
They are only making the 85s at this point.
Changing weight will require suspension adjustments as well as working on weight distribution to balance the car properly.
If you can afford it, I wouldn't go lower than the 85kw pack.
The lowest I'd go as a last resort would be a 60kw pack.
Given the real life mileage you can extract from it without sacrificing driving dynamics and comfort, and taking capacity degradation over time, 85kw is probably the best choice at this point.

Timo | 17 novembre 2012

kWh = energy, kW = power.

HenryT2 | 17 novembre 2012

My understanding is that the battery is made up of many small cells. Consequently, I would think that the easiest and most cost effective manner to reduce the battery size would be to either simply reduce the number of cells or have cells with smaller kWh each. Then, increasing should be relatively easy as well. I would think this would have a fairly minor effect on the weight/weight distribution and would not require a major modification of the suspension.

I say "relatively". I don't expect it would be a minor task. But lets say that there is a boost in potential battery power by double or triple over the course of the next five to ten years. It seems it would be worthwhile for Tesla owners to upgrade their batteries even if it were a bit of an ordeal. At that time, I would imagine that it wouldn't be that much more difficult to swap a 40kWh battery for an improved 150 or 250kWh if the engine is the same.

Imagine a 150 or 250 kWh battery! If the 40-85kWh battery changes the acceleration from 6.5 to 5.6 0-60, a 250kWh should put it into warp territory! Warp factor 2 Mr. Sulu!

ChasF | 17 novembre 2012

I completely agree, Henry T....2

I am getting the 40kWh for all the same reasons you are considering. I am convinced there will be upgrade options in a few years and would rather not spend an extra $20K that will rarely get used while depreciating quickly. That $20K should translate into significant future capability if my driving needs change. For now, I should be plenty satisfied with the 40kWh range and performance.

Sudre_ | 17 novembre 2012

Please don't come back at Tesla 3 years down the road when they tell you no upgrade on your 0-60. It has been stated by Tesla that you should get what you want and not expect the ability to just upgrade like you are thinking. I do not remember which thread this has been discussed in before. You might be able to get the bigger battery but not the better car.

Do not assume you can just get a better car in 3 years by installing a bigger battery. Elon has indicated to get the performance you want now.

ModelS3P | 17 novembre 2012

Sudre_: I have confirmed more than once with Tesla that a bigger battery pack down the road will get you the increased 0-60 time; however, I agree that the potential battery upgrade options have not been figured out yet (timing or availability). Given that they can supposedly swap out a battery pack in about 15 minutes, I am betting that upgrades will be an option in the future, but probably not for a few years. I have never heard them say "get the performance you want now," but I have heard them say "get the range you expect you will need now."

In my case, I am not buying this car for performance, and I will be using this as my 95% of the time car, so the 40kWh battery pack will be plenty for at least the next 7-8 years (warranty on the battery). Then, I am assuming that I will have additional battery options at that point. It is a risk I am willing to take for the cost savings today.

Timo | 17 novembre 2012

Bigger battery in kWh doesn't necessarily mean bigger battery in kW. It depends of the power density of the battery and if that stays same then there is no change in power while range increases.

Tesla probably doesn't want to say this or that about that because they simply don't know what happens.

Also it depends of the capabilities of the wiring, PEM and the motor, so even that battery itself could increase power output it is possible that you can't use it.

BYT | 17 novembre 2012

I wonder what happens in the future for P85 Model S' and battery updates/upgrades or more importantly, downgrades?

HenryT2 | 17 novembre 2012

Myself, I'm not EXPECTING that there will be an option to increase the battery size or performance in the future. But just from an engineering standpoint, it seems that if the engine is the same, and eventually batteries must be swapped out or better capacity batteries are available, it just seems feasible that the 40kWh should be able to get the same batteries that are available to the other models.

HenryT2 | 17 novembre 2012

I test drove the P85 the day before yesterday (I wanted to make sure I wouldn't have any regrets). It's as awesome a performance car as I've ever driven, but I won't miss it that much. The acceleration was actually a little scary. Too much for simply taking off from traffic lights, and overkill for overtaking on the highway. Felt GREAT. And if you live in an area where you can floor it frequently, you might find it more practical than I do. But for me, it's $35K more than the 40kWh. Almost enough to buy a second 40kWh or Model X.

ModelS3P | 18 novembre 2012

Timo: Here is the text from the e-mail I received from Walter Franck where he discusses the PEM and hardware:

The power electronics, inverter and motor will be the same between the 3 batteries. Model S comes standard with a 10 kW charger and can be upgraded to the 20 kW twin charger after delivery. There will be firmware differences between the different battery packs, but hardware will remain the same. Model S Performance will have different hardware outside of the battery to allow the increase in acceleration, this cannot be upgraded after delivery.

The one important difference to keep in mind is Supercharging. This requires special hardware that bypasses the on-board chargers as well as more robust wiring capable of handling 90 kW of power. When built, the 40 kWh will not have the hardware required for supercharging and cannot be upgraded afterwards with that hardware. So while possible to upgrade from a 40 kWh battery to and 85 kWh for extra range and an improved 0-60mph, supercharging will not be possible. A 60 kWh vehicle purchased with the supercharging option can be upgraded to an 85 kWh and have access to the supercharge network.

Note that it will be some time before we have the flexibility as a company to upgrade batteries, our recommendation is for our customers to purchase the battery that best meets their current and future needs.

DouglasR | 18 novembre 2012


While that email is very informative and helpful, it does not answer the question of whether a performance vehicle has a different PEM or just a different inverter.

Dennis in Boulder | 18 novembre 2012

Interesting forum, one thought for the future that I think would be interesting is on board charging. Does anyone know how much power the electric motor pulls from the batteries? If you had a power source on board, what would it take to not even use the power stored in batteries?

I say this because of companies like Bloom energy who may very well have technology to provide fuel cell power generation in small enough devices to power a car. Any thoughts?

jerry3 | 18 novembre 2012


Why bother with a battery at all then?

The big problem with fuel cells is that they are very inefficient, requiring far more energy to produce the hydrogen "fuel" then they produce.

Timo | 18 novembre 2012

Fuel cells are also a lot more complicated, more expensive, have worse volumetric energy density and have weaker power density than batteries and they also degrade over time and require replacing just like batteries do and they need "gas stations" which are nowhere to be found.

In short they lose to batteries in all possible ways.

jerry3 | 18 novembre 2012



Brian H | 18 novembre 2012

Small fuel cells, at least, can use methanol as a hydrogen source, making many interesting military applications possible. Batteries can occasionally be solar-recharged in the field, but that is a far less convenient process, hence less functional, hence more dangerous.

ModelS3P | 19 novembre 2012

@DouglasR: my post was not meant to be informative on the performance version, just trying to shed light on the identical PEM/hardware for the 40, 60 and 85 kWh non-performance versions.

DouglasR | 19 novembre 2012

@Longhorn92: understood. But I'm still curious about the PEM/hardware for the performance version.

David M. | 19 novembre 2012

There is no engine.
There is an AC motor.