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Installing "high performance drive inverter" in the future on a 85 non perf?


Roadster + Sig Model S
May 17, 2009
You are almost certainly better getting the Performance version now if that's what you want. You won't be able to upgrade to a performance through Tesla at least in the future (I'd double check with Tesla but pretty sure that's what they would say).


Model S 85KW, VIN #2236
Aug 1, 2012
San Jose, CA
Not to mention the fact that even if you succeeded, the odds are high that nothing would change (e.g. car would draw the same power through the system), the car would misbehave because it thinks it's got the stock inverter and now it doesn't, or the car would detect the difference and shut down because it knows it doesn't know how to handle the new inverter.

BTW, this isn't an EV vs. ICE thing. Modern ICE cars have so much complex software controlling the powertrain that you can't do a turbocharger upgrade and expect things to work w/o massively reconfiguring the software (MAP data, etc.).

If you own or work in a top-tier tuning shop, this might be feasible. And you'd probably need support from Tesla because they're not likely to be using standard (ICE) engine control software. If you don't, this idea is beyond stupid.


Moderator - Model S & X forums
Not at all a stupid idea. Difficult to implement, yes. Probably not realistic, yes. I'm quite sure the computer reprogramming would be the biggest hurdle. I think replacing the inverter would be pretty simple. There are some pretty sharp folks out there that might be able to figure out the programming, but getting that past Tesla and avoiding them reprogramming is going to be tough. And don't even think about keeping anything related to the drive train under warranty.

Also, isn't the motor in the Perf different? hand wrapped or something.

I don't doubt that someone's gonna grab a salvage Model S, once available, and try something like this though.


Dec 19, 2008
The OP never mentioned anything about tackling this himself. Some here need to lighten up.

To answer the original question. Yes, it will most likely be possible. Will it be cheap? No.

BTW, most new ICE cars are easily modified. You definitely don't need to be a tuner shop to do so.


Burrito Founder
Nov 10, 2011
Has anyone heard or is aware of this possibilty in the future. Cost of doing so?
I'm nearing my decision and it would seem to be a better option to purchase the 85 kw and attempt to make it go faster in the future.
Is that an option?
Are you asking whether there might be an after-market or future-from-Tesla offering of a drive inverter that is even better than the current Performance offering?

Or are you asking whether you can buy non-Perf now and upgrade later through Tesla?

Or something else?


Model S 85KW, VIN #2236
Aug 1, 2012
San Jose, CA
Yes, replacing the inverter is the easy part. And yes, I think the motor is wound differently so it can handle more power. If correct, you'd need to replace both.

I think the software is not going to be nearly as easy to handle as you'd think. It's not just straightforward acceleration.

Regen, hill hold, creep, power management and who knows what else all have tie-ins to the engine control software.

Yes, it's doable. It's gear and software. Anything's doable. But it's going to be a cast-iron pain to get right. *If* Tesla designed their software and supporting interfaces to handle this sort of thing, it might not even be too bad. If the proper interfaces exist and if you know what they are and how to use them properly. Big if's. Then you have to test it.

Speaking as someone who's been in business-critical software engineering for decades, I wouldn't want to get behind the wheel of one of those cars or be anywhere near one.
I asume the reason would be to aquire faster 0-60 speed - right ?

then there may be 2 alternative routes to go.
1. change the diameter of the tires to a smaller size (should be fairly easy - just fit low profiles to origianl 19" wheels)
2. modify the internal 1 gearbox to have lower gear ration (may be difficult)
these modifications will give you a faster 0-60 time but at same time lower the max speed.
in fact it might also give you a few extra miles, asuming less heat wasted in ac inverter while normal driving (might be minor)

#1 is easy and relativly cheap
the stock tires:
Tyre dimensions: 245/45 R19
reveals a circumference of 2207 mm

35 mm low profile 19"
Tyre dimensions: 245/35 R19
reveals a circumference of 2055 mm

ration is 7% longer/shorter - so removing 7% of you top speed (116 miles on top) and gaining a 7% reducion in gear ration (increase torch by 7%)
Im not shure what this will translate 0-60 into - but I guess your 85 would perform near or simmilar to a P85

35 low profile could then be some sort of sports tires - who will be the first to try ?:cool:

this could ofcouse also apply for the P85 giving it 7% increased torch and even lower 0-60

- - - Updated - - -

btw. Im not a tire expert, so take my suggestion as an inspiration and invest som time to dig into the matter.
maybe ask in this thread if 35 mm low profile tires would work on these alternative whels


(S85-3/2/13 traded in) X LR: F2611##-3/27/20
Supporting Member
Mar 8, 2012
#1 is easy and relativly cheap
the stock tires:
Tyre dimensions: 245/45 R19
reveals a circumference of 2207 mm

35 mm low profile 19"
Tyre dimensions: 245/35 R19
reveals a circumference of 2055 mm

Don't do this (as in very bad idea). A 245/35R19 will not have the carrying capacity and will fail sooner or later (sooner if you are using it for performance reasons). I've seen far too many tires fail because they were too small for the vehicle.


Well-Known Member
Dec 8, 2007
Have any of these mods been done to the Roadster?
Roadster Sport has a different motor so upgrading the inverters alone will not do the trick. If I recall correctly, there is no difference in the motor for the 85kWh and P85, only the inverters (and perhaps wiring).

Of course, as mentioned the software is the issue (you have to tell the car the more powerful inverters are there). For ICE cars you typically get a chipped ECU and have a tuner map/tune it. Probably sometime in the future this will be available for EVs, but at this point it's non-existent.
I still belive it would make sence to swap the standard 19" tyres out, and instead get som lower profile tiers on - the gear reduction going from 45 mm to 35 mm is aprox 7,5%

Tyre dimensions: 245/* R19

since acceleration is direct influenced by gear ration you will gain 7.5% faster acceleration (and 7,5% lower top speed)
a standard 85 will i practise be able to do 0-60 in 5 sek (reported) - this could go down to 4,6 sek
a P85 is reported going 0-60 in 4 sek, and potentially it could go down to 3,7 sek.

Roadster potential is pressent in the p85 just by swapping out to 19" wheels and having 35 mm profile tyres. - BTW. I can not understand why this should have anything with carring capacity to do - 21" are factory delivered with 35 mm profile.only problem I see is that the speedometer will be miss alligned and showing 7.5% faster than actuall driving speed and that milage counter will do the same - if Tesla could give a software option to adjust this, it would be no problem.
I belive this would be the "only" option to upgrade the acceleration in the future. (or changing the build in gear reduction box))

- - - Updated - - -

just checked out the load index on the original performance 21" tyres - it is 96Y in the front and 101Y by the rear.
I asume as long as you stick to these numbers your 35mm profile will not be dammaged by load - so the big question is, if it is posible to find such tyres


Tech Specialist
Nov 29, 2012
I was told on the factory tour in January that there is only one motor for all S versions, including the P85. Of course, this is not an Tesla official statement, but seems reasonable. I've never heard differently, unlike the Roadster than did have a special motor for the performance version.
I'm wondering the same thing. I don't *think* I need the P85. but it would be nice to know that one day I could change my mind. In my perfect scenario, all the work would be done by Tesla and they'd update the software as needed. It's too bad it's ten grand... If it were 5 grand I'd probably do it at this point... :D

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